I figure I'd give this thread a quick update. We did the catalytic converter stew with citric and oxalic acid in July of 2019, and our 2002 Forester, which previously had a nagging problem, has been P0420-free ever since. 18 months and counting... ~ Silke ~. '02 Forester S 5MT - "Cooper". '11 Honda CR-Z 6MT - "Kat".It’s a 2012 forester premium. In the last year she had the engine gaskets replaced. Then the catalytic converter, the alternator, radiator and battery. So she was over it and gave it to me. I had to drive it from Louisville to Wisconsin. And a couple hours in the check engine, traction control light (both solid) and cruise control light ...The nerdy and keen eyed will notice I omitted the valve lash adjustment on these 2008-2010 Subaru products with the 2.5L engine...because nobody and I mean N...Back to your P0420. I'd guess it was caused by the break in the exhaust pipe allowing oxygen to reach the rear O2 sensor. Bottom line, not the CAT or the rear O2 sensor fault. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester.A P0420 CEL code comes from the rear O2 sensor, usually meaning there's too much O2 in the exhaust. The usual suspect is a leak in the exhaust, or an overly rich condition. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester. Show Less .Ran the code and got " P0420 - Catalyst System Efficiency Below Threshold Bank 1". ... We’re the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of …CLEAN Your CAT - Fix stubborn P0420 Here's what I did: On 2005 Forester XT with P0420, 1. Removed downpipe/catalytic converters. 2. Separated into upper Cat and lower Cat. 3. In a 5-gallon bucket, mixed 4 gallons water, 10 oz. Citric acid and 7 oz Oxalic acid. (Purchased on Amazon - $20) 4. Soaked main Cat in acid overnght, rinsed completely ...#1 · Jan 1, 2014. A short time ago, in a forum not too far away, a 2006 Forester owner inquired about a P0420 CEL code. I responed... dave5358 said: An 0420 error is low cat …PO420 code. Thanks for taking the time to help. I have a 2004 Outback 2.5L automatic. J259. Code P0420. I've replaced the bank 1 sensor 1 with a Denzo brand. I've ran 2 different cleaners through the gas tank. I got the car with a blown head but had it fixed. I replaced the sensor after the head was fixed.Here is the service manual blurb on P0420. Attachments. P0420.pdf. 38 KB Views: 56. Save Share. Like. S. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester. Show Less .Systems often disable with a check engine light, so the P0420 caused the VDC and cruise to disable. Once that code disappeared those systems resumed nominal ops. why the P0420 code was set might be the main question. That's weird.Dec 26, 2009 · 2.5x_sleeper. 45860 posts · Joined 2007. #5 · Dec 26, 2009. My guess is a failing front O2 sensor, causing an over rich condition. This would give you the gas smell & would overwhelm the CAT. The rear O2 sensor, which monitors the CAT, would give you the P0420 CEL code. Sounds like what happen in my '03. :wink:Twice on one Subaru (Outback 3.6R) and once on another (Impreza) the P0420 code has been cured by replacing the downstream O2 sensor. Neither vehicle was experiencing a power loss ... We’re the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru ...2017-18MY Forester 2.5L 2019-23MY Forester 2018-23MY WRX 2019-21MY Ascent SUBJECT:DTC P0420 Diagnostic Procedure INTRODUCTION: This Service Information Bulletin announces diagnostic service procedures to be followed when DTC P0420 (Catalyst System Efficiency Below Threshold Bank 1) is detected by the Engine Control Module (ECM).2015 Forester Touring Key fob problems: 0: Sep 2, 2021: 2015 forester A/c problems: 1: Aug 24, 2021: Need Hatchback tent for a 2015 Subaru Forester: 0: Jun 27, 2021: 2015 2.5i Limited Forester - Head Gasket Replacement or New Engine: 0: Dec 5, 2020: Best all weather tires for a Forester 2015: 4: Sep 11, 2020: 2015 subaru /forester /4dr cvt 2.5i ...The CEL would turn on and off occasionally so I changed the Wires, Plugs and coil pack and went ahead and did the 2 - O2 Sensors. Now over time I have earned 2 additional codes for my efforts. I have all three, (P0301, (Cylinder 1 Misfire Detected), P0303, (Cylinder 3 Misfire Detected), & P0420, (Catalyst System Efficiency Below …The P0420 is a finicky code. There is a range of "acceptable" parameters that Subaru has set. If the O2 sensor sees a value that is outside of that range, even for just a fraction of a second, you get the P0420. Adding the extension doesn't stop the O2 sensor from working, it just doesn't get the immediate read, but more of a mixed read.A p0420 code can be a air leak or exhaust leak before or after the Cat , and an exhaust system on that car should not have any flex pipes , ... 2006 Subaru Forester X, 2.5 non turbo, automatic, 288K miles. In the past, I started experiencing P0420 codes around 190K miles. After experimenting with different gas tank potions and solutions (even ...Catalytic Converter fits Subaru Forester Impreza Legacy Outback 2006 - 2010 2.5L | eBay Our converter manifold is compatible with the2005-2010 Subaru and 2006 Saab 9-2X 2.5L, helpful in upgrading the exhaust system to improve vehicle performance. ... Car is not overly loud or anything. Doubt that really has anything to with the p0420 code as (I ...P0420 Diagnosis Sleeper vdc. ... 1999 Subaru Legacy GT, 2.5L EJ25D DOHC, Manual-201,000 miles-I replaced the original engine with a used 92,000 mile engine 500 miles ago-Ran great for those 500 miles Over the past week I have noticed very slight engine hesitations while accelerating. Drove it one morning and it ran fine aside from a couple of 1 ...I recently purchased a 2005 Subaru Forester XS, and it's beautiful! But after driving it 30 miles, the CEL popped on & the Cruise Control Light started blinking. I got home and plugged in my reader to find out it was the lovely P0420. After reading the live data, I saw my "Oxygen Sensor Current (B1-S1)" fluctuates between -127.918 mA & 127.871 mA.Subaru Mechanic: Ronnie. Normally you can replace the front converter without having to replace the downstream converter with no issue. The common one to fail and set the P0420 is, in fact, the front converter. If the only code your getting is the P0420 then I would just replace the front converter and usually, you will be fine with no issue.In all seriousness, the P0420 is only good for making your wallet lighter by either ~$100 for a new sensor or several times that for a new cat. I've never seen a P0420 actually point to a bad catalytic converter. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability ...When your Subaru Forester's dashboard lights up with the P0420 code, it indicates a problem with the vehicle's catalytic converter efficiency. However, understanding and addressing this issue can extend the life of your car and improve its performance. Here's a detailed guide on what the P0420 code means and how you can fix it. Shop Car Code ...The P0420 code is set by a reading from the downstream O2 sensor. That's all that the downstream O2 sensor does, is monitor the efficiency of the cat. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester.Used 2020 Subaru Forester Pricing. Used 2020 Subaru Forester pricing starts at $18,335 for the Forester Sport Utility 4D, which had a starting MSRP of $25,505 when new. The range-topping 2020 ...Just a note...P0420 codes are typically caused by faulty catalytic converters, they are warrantied for 8year/80,000 miles. Don't pay to fix it if its still under that warranty. 2021 Forester Sport, 2014 Forester Limited, 2016 Crosstrek Premium, 2013 BRZ, 2020 GMC Canyon Denali Diesel. J.63 posts · Joined 2011. #1 · Jan 10, 2012. I have a 2004 OBW and it keeps throwing the P0420 catalytic system below threshold code. The car is bone stock. It is drive by wire and has the California emissions on it. It's engine is a model EJ259 if I remember correct. I've tried using the anti-foulers, and even the electronic fixes in the rear ...4 days, 1 subaru wideband sensor, and 3 drive cycles later, I have clearing subaru readiness monitors down to a T. And the wide-band that came with my AEM failsafe gauge is looks to be the same model as the subaru wideband, except the resistors are different. But, the P0420 code was still there.I got a P0420 code but my voltage was bad due to factory grounds being weak ... Related Subaru Forester Subaru Subaru Cars and Motor Vehicles forward back. r/SubaruForester. r/SubaruForester. This is a place where all Forester owners can meet and discuss Forester news, mods, and general driving experiences whether its track, offroad or daily. ...A p0420 code can be a air leak or exhaust leak before or after the Cat , and an exhaust system on that car should not have any flex pipes , ... 2006 Subaru Forester X, 2.5 non turbo, automatic, 288K miles. In the past, I started experiencing P0420 codes around 190K miles. After experimenting with different gas tank potions and solutions (even ...Shortly after we bought our 2005 Impreza Outback Sport with 253K miles last summer it started throwing P0420 codes and after a reset, the code returns after 8- 10 miles. On our 2003 Forester we bought a year ago at 223k miles, it threw a P0420 earlier this year, then again about two weeks ago. I ...It’s a 2012 forester premium. In the last year she had the engine gaskets replaced. Then the catalytic converter, the alternator, radiator and battery. So she was over it and gave it to me. I had to drive it from Louisville to Wisconsin. And a couple hours in the check engine, traction control light (both solid) and cruise control light ...Mar 21, 2011 · I figure I'd give this thread a quick update. We did the catalytic converter stew with citric and oxalic acid in July of 2019, and our 2002 Forester, which previously had a nagging problem, has been P0420-free ever since. 18 months and counting... ~ Silke ~. '02 Forester S 5MT - "Cooper". '11 Honda CR-Z 6MT - "Kat".2008 - O2 Sensor and P0420 Cat Code? ('06-'08) Jump to Latest Follow ... Subaru Forester Owners Forum. 2.6M posts 191.2K members Since 2006 We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester. ...Forester 2001 L - Stock 101k Miles P0420 - Catalytic Converter Efficiency Below Threshold The forester has been throwing this code for a few months now, typically shows up on long highway runs (but to be fair, that is the vast majority of my driving). I bought a scanner from scantool.net...Jan 18, 2011 · Hi, i have a 2008 subaru forester that has been having the po420 code come up (traction control, check engine and cruise control light). Only started just before Christmas on a long drive has happened 3 times since, engine runs rough when i get the lights turned off and has stalled a few times, runs really rough when idling at the lights or just pulled up somewhere and put in park.Just a note...P0420 codes are typically caused by faulty catalytic converters, they are warrantied for 8year/80,000 miles. Don't pay to fix it if its still under that warranty. 2021 Forester Sport, 2014 Forester Limited, 2016 Crosstrek Premium, 2013 BRZ, 2020 GMC Canyon Denali Diesel. J.Hi all, I have a 1999 Outback S/W 95K. I bought it used and the head gasket was changed by previous owner at 86K. Shortly after buying it two months ago the check engine light went off. The code was P0440 - Evap Emissions Malfunction. After searching the internet and talking to mechanics I see it is a difficult problem to diagnose and correct.5784 posts · Joined 2018. #2 · Apr 12, 2023. There is a whole thread on this forum about the P0420 code, what can cause it and how to diagnose the cause. If you take the time to read the first 10 to 20 posts of that thread you may be able to diagnose the cause. The code can be caused by bad fuel, faulty O2 sensors, poor electrical connections ...For a couple of months now Ive had P0402 P0420 Come on. Often shortly after refuelling. My car has run 225000 kms by now. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester.January 2, 2023 by Jason. This page is meant to help you troubleshoot the Subaru Outback P0420 trouble code. It covers the P0420 code’s meaning, symptoms, …Check engine light - P0420. I have an 2005 subaru forester with 82000 miles and the Check engine light is on and cruise control is flashing took it to the dealer and they replace the oxygen sensor after driving the car for about 20 mins the lights came back on.Any ideas on what should I do need help. So I went out and bought an OBD 2 …Jan 1, 2014 · There's some good information from that post onward. The gist of these messages and threads is this: to deal with a P0420 code on 2005+ vehicles, the ECU should be remapped to exclude this code, rather then using the $5 fix. The reasoning is that the rear O2 sensor is actually used to manage the engine, at least a little bit, rather than just ...I have a 2011 2.5x (65k miles) and the CEL light came on after filling up with gas a few weeks ago. I checked to make sure gas cap was tight and CEL was still on. I had the codes read and it showed P0171 & P0420. I reset the codes to see if it might have just been the gas cap, but CEL came back on. I've noticed a decrease in gas efficiency ...I have a 2009 Forester 150k miles that throws a P0420 code, it happened 4 times over the course of six months and has gone away after a few days until now. ... Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester. Show Less . Full Forum Listing.Jeff04FXT Discussion starter. 388 posts · Joined 2006. #1 · Feb 16, 2010. The engine shakes at idle (~600rpms),also if you rev it will drop down in rpms below 500rpms almost stall.Also i'm getting some surging at lower rpms and slowers speeds.P0420 Hard to start Help! 2002 Forester L. 136k Manual transmission. Bought this car about a month ago (first subaru) about a week into owning the car it developed a small intermittent start issue. Basically when the engine is WARM it will crank 2-3 times then misfire. Turning the key off then back on it almost always cranks once and starts ...Jul 18, 2017 · Also, P0420 can be the cat, but it can be a number of other things including rear O2 sensor, intake/exhaust leak messing with the air fuel ratio, spark plugs, fuel ...My '11 Foz has popped the dreaded P0420 and given that she's at 162k, I may as well toss a new cat in at this point. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester. Show Less . Full Forum Listing.This low kilometer Subaru Impreza flags a P0420 Catalyst efficiency fault code very quickly. The rear O2 sensor would behave almost like the catalytic conver...in this video I will share with you how to diagnose and fix the cause of a P0420 and P0430 Trouble Code on a Hyundai Sonata#Catalyticconverters #Catalyticcon...P0325, P0420, and passing California smog test. For some months now my '02 Forester L has been giving me the P0420 code (and just today it also gave me the P0325). I haven't done anything to address the issue other than to turn off the CEL using my Actron scanner, but now it's time to register my car in California for the first time and so I ...2001 Subaru Outback LLBean P0420 Diag - YouTube ... I was also reminded why I opted out of owning a Forester. You can't just tilt the seat up to get to the harness, and too much to remove from the rear to get to the fuel pump. But it all worked out good. If you're in Austin, TX and having difficulties with the dealer or any shop, hit me up. ...HELP: Code P0420. My 2009 forester has the "cruise" light blinking and a solid traction control off and check engine light. I got the diagnostics ran and it came out with "P0420: catalyst system efficiency below threshold bank 1". This happened to me last year but ignored the symptoms for about a month and then had to get it taken in ...And it was the same as usual, P0420 and P0442. I've had P0420 since I got the car in june 2011, but didn't bother as, according to my mechanic, "it's just because the computer doesn't recognize the aftermarket catalyst". Back then, gaz mileage was on close to manufacturer's specs (11L per 100km city = 21MPG, ~9L/100km highway = 26MPG) so I ...Hi all, I have a 1999 Outback S/W 95K. I bought it used and the head gasket was changed by previous owner at 86K. Shortly after buying it two months ago the check engine light went off. The code was P0440 - Evap Emissions Malfunction. After searching the internet and talking to mechanics I see it is a difficult problem to diagnose and correct.In this video we discuss a common Subaru fault code associated with variable valve lift systems on the 2.5L engines. This code is common across 2006-2011 Sub...Several factors can trigger the P0420 code in a Subaru Forester. Understanding these causes can help in diagnosing and resolving the issue effectively. In detail: Some common causes include a failing or damaged catalytic converter, oxygen sensor issues, exhaust leaks, engine misfires, or even a faulty fuel system.The code P0420 in the Autozone readout specified bank1 so I took a chance on the mod for just the sensor behind the passenger cat since AZ only had one package in stock. If the code returns, I will do the driver's side as well as the rear sensor behind where the dual exhausts join, hopefully on a warmer day. Thanks for the help.Forester. SỨC MẠNH ĐỘNG CƠ. Thiết kế phẳng nằm ngang của động cơ Boxer mang lại sự cân bằng và khả năng kiểm soát tối ưu với trọng tâm thấp, đây là sự khác biệt độc đáo cho khả năng vân hành hiệu quả được Subaru sử dụng trong hơn 50 năm qua. TÌM HIỂU THÊM.P0420 Diagnosis Sleeper vdc. Save Share. Like. ... Welcome to the Subaru Outback Owners Forum, we have tons of information about your Subaru Outback, from a Subaru Outback Wiki to customer reviews. Show Less . Full Forum Listing. Explore Our Forums. Gen 5: 2015-2019 Problems & DIY Maintenance Gen 4: 2010-2014 Gen 6: 2020-present Gen 3: 2005-2009.Jul 24, 2020 · Our family has 3 Subarus. On our 2009 Impreza 2.5i I was getting the p0420 code. We drove it that way for several months not knowing if it was the Catalytic Converter or one of the o2 sensors. I called the local Subaru dealership and they said I would have to pay for a diagnostic and a replacement Catalytic Converter if that was the problem.Right after I got the new PAK file, my car threw a P0420 code. Took it back into the dealership and they confirmed the data stream showed the CAT's were under performing. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester. Show Less ...A P0420 CEL code comes from the rear O2 sensor, ... We’re the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru …For the past six months or so on my 02 Forester L, my CEL has been going off and on. When on, it gives the P0325 and P0420 codes. I know what these represent; what I don't know is whether there might be a relationship between the two. That is, what might cause them to go on and off at the same...Aug 20, 2020 · Tech Notes. As the code description implies the P0420 code means that the vehicle's control module has detected that the three-way catalytic converter is not working properly (is not as efficient as the factory is expecting). Replacing the oxygen (O2) sensors may sometimes fix the code, but in most cases the catalytic convert needs to be ...Back to your P0420. I'd guess it was caused by the break in the exhaust pipe allowing oxygen to reach the rear O2 sensor. Bottom line, not the CAT or the rear O2 sensor fault. ... We're the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of the Subaru Forester.It's a lot to digest, but I highly recommend clicking on this P0420 thread started by Cardoc over on the Outback forum. Cardoc and Plain OM are the primary gurus and are both still active there. Tons of good info. In the first 70 or more pages (1400+ posts), there are many references to Romraider software to get OBD data.The P0420 engine code indicates the catalyst system efficiency is below the threshold (Bank 1). A P0420 code indicates a problem with the catalytic converter, more specifically. The purpose of the catalytic converter is to break down harmful pollutants created during the combustion cycle. By using fine platinum and gold meshes to filter exhaust ...Subaru Forester 2014 I have a cel with code p0420 on and off,CEL came up drove for 70KMS and it went off the moment I had filled in gas. It comes on and off. Should I take it to mechanic or keep drivingIndices Commodities Currencies StocksP0303 and P0304 are misfires on cylinder 3 and 4 (the rear cylinders). P0420 is a cat efficiency code caused by the misfires, too much unburnt fuel going through the exhaust. Check the spark plugs (especially the gap), wires, and ignition coil. It could also be a problem with the fuel injectors.Ran the code and got " P0420 - Catalyst System Efficiency Below Threshold Bank 1". ... We’re the best Subaru Forester Owners Forum to talk about the best years of the Subaru Forester, modifications and reliability history of …It only takes a pinhole in the exhaust, near the rear O2 sensor to trigger the P0420 CEL code. The only function for that O2 sensor in your '01 is to monitor the efficiency of the CAT... to check for excess O2 in the exhaust flow. If your gas mileage & engine performance is normal, then I'd look for holes in the exhaust.The P0420 code is a diagnostic trouble code (DTC) related to the efficiency of the catalytic converter. This code appears when the vehicle's engine control module (ECM) detects that the catalytic converter is not functioning as efficiently as it should, based on the readings from the oxygen sensors located before and after the converter.This Service Information Bulletin announces diagnostic service procedures to be followed when DTC P0420 (Catalyst System Eficiency Below Threshold Bank 1) is detected by the Engine Control Module (ECM). If DTC P0420 is found to be stored in the ECM, follow the diagnostic procedures outlined below.You are seriously overthinking this problem. On Subarus, a P0420 code implies low cat efficiency. Your catalytic converter could actually be on it's last gasp, or it could be a variety of other things. For a 2003 vehicle, it's hard to guess exactly what's what.The most common signs of bad mass air flow sensor (MAF) in Subaru Forester are loss of power or slow acceleration, engine hesitation or jerking during acceleration, erratic idling, misfires, poor exhaust emission values and sometimes black smoke comes out of the tailpipe. The mass air flow sensor is part of the engine's intake system and is ...quick question im in the process of having my cat converter swapped because of the check engine light with a P0420 reading. This might be a nube question but i need to figure it out asap or i wont pass inspection. ... I am in need of help with a 1999 Subaru Forester upstream o2 sensor. The shop that rebuilt the engine replaced the stock with ...Forester 2001 L - Stock 101k Miles P0420 - Catalytic Converter Efficiency Below Threshold The forester has been throwing this code for a few months now, typically shows up on long highway runs (but to be fair, that is the vast majority of my driving). I bought a scanner from scantool.net...The p0420 code means that the catalytic converter is below threshold and is , Got mine back after the dealer replaced the catalytic converter under warranty , 104 posts · Joined 2008. #2 · Oct 3, 2011. I as well have been dea, When I started up my Forester (2017 2.5i Premium) this mor, If you want the P0420 CEL electrical fix, take a look at thi, If the check engine light comes on in your Subaru there is always a corresponding code, For the past six months or so on my 02 Forester L, my CEL has been going off and on. When on, it give, 2002 Subaru Forester S P0420 Own a 2002 Forester S (pur, This is a 2011 Subaru Forester with approximately 147k, Subaru Forester owners often find themselves needing to change the cl, As to the P0420 CEL code, take a look at these threads: • P, The $5 fix is installed on my 2000 Forester but it hasn't, Im getting the p0420 in an 04 forester 2.5xt turbo. Iv, Here is my story. I have an 01 S with manual trans with 227,000 k, 2013 Outback P0420 code. Hello, I am new to this forum an, VSurfn. 1329 posts · Joined 2014. #2 · Jul 22, 2018 (Edited) P042, The Continental ContiProContact tire is the best overal, I'm new to the forum and trying to find answers to a few issues wi.