Subaru - Forester :: Shuddering During Acceleration - PO420 Code
May 27, 2015
I purchased a 2001 Subaru Forester about 4 years ago. Within 48 hours of buying it from a dealer, the check engine light came on showing the PO420 code. The car was running fine without any problems and it was suggested to us by 2 independent mechanics that Subaru is notorious for throwing this code, so we didn't investigate it any farther besides doing a fuel system clean/flush that was offered to us by the dealer.
Lately, the car has started sort of shuddering during acceleration so we figure it's time to look into this more, but just trying to figure out where to start. From what I understand, this model has 2 catalytic converters and 2-3 O2 sensors. I've been reading as much as I can on the topic and watching videos trying to figure out our options and whether we should try replacing the O2 sensors first or just go for replacing the whole shebang. I know we cannot afford the pricey repair of it all right now so the car will have to sit for quite some time before we can do that; however, if we can figure out how to do it ourselves, we could get it done much sooner.
My questions are:What is the likelihood that this could still be an O2 sensor issue considering the shuddering when accelerating?
What other signs do I look for besides rattling in the cats to know they might be bad?
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I have a really weird problem with my car. Every time that I apply the brakes, I get a bit of a shudder. It just started a couple of weeks ago and we checked the brake pads which were fine and the bearings were good as well. What could be causing this problem?
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My 2004 Outback now has 120K, has always been maintained and repaired at the dealership (except tires and battery), and has always run great! I've had the plastick-y parts replaced over the last few years including head gaskets when one cracked and made smoke. In July I got a jump from a AAA tow truck, who said my battery tested as needing replacement.
In September my check engine light went on, and the dealer found the code PO420-catalyst system efficiency. They didn't seem to look any further into causes. The cat converter replacement was to cost $2521. They reportedly tested the battery as OK as part of their routine checkup. I declined the new cat converter till learning more. Meanwhile, my check engine light seemed to cycle on, then off, then on, then off . . . every several days.
In December I had the battery checked at Sears, who replaced it under warranty. So I guess it wasn't okay after all. After that my check engine light stayed off for somewhat longer than usual, then back on for most of January. I was just about to give in and get the repair done when it cycled off briefly a few days ago.
I've lost trust in the dealership because of their battery check which differed from others before and after theirs; and for their lack of specific diagnostics. The light is back on and I don't know what to do next.
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CEL came on last night, OBD code PO420, truck is an 06 f250,5.4? Btw, truck running rough, no power on acceleration, in gear at idle, runs rough....
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My 2011 Forester makes a rattle sound each time I accelerate either uphill or on level ground. The sound is reminiscent of the pinging sound from cars from years ago when we were told to use a higher octane gas. It's only at the start of the acceleration, not continuous. The sound seems to come from below the car, either under the hood or under the body, not inside the passenger compartment. Most websites say loose heat guards, but this would mean I'd hear the rattle throughout the acceleration, wouldn't it? Brought It to the dealer twice and they couldn't hear anything. No surprise. I hear it with my 2013 Legacy also.
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I purchased a 2012 Subaru Forester 2.5X Premium (automatic transmission) in November 2011 with 4 miles on it. Since the get-go it has had issues, but we thought that some of them might work themselves out as we broke the car in (which we were religious about). At the first oil change, we told the dealership about the issues we were experiencing and got the expected "the computer doesn't say anything is wrong" and "we couldn't replicate the problems" excuses. We were told to bring it back if the problems continued. Well, they've gotten worse. Here are what we are experiencing:
- Erratic shifting. I commute from the mountains to the city every day, so I need power from the car. Sometimes, when I'm heading down a hill and I tap the gas slightly to give myself a little boost, the car will suddenly downshift, even though it was sitting at 2500 RPM and didn't need to get any extra power beyond more fuel. Going up the hill is worse, as if you are not actively accelerating (including if you are trying to maintain a constant speed), it will upshift on you and you lose all power, so it will need to downshift to make up for this. It does this constantly for the entire drive home. Everyone who has driven this car in the mountains has experienced this.
- Jerky transmission. When the car shifts, it is super harsh and tends to throw you forward or back. Even when on flat ground it shifts roughly.
- Sluggish acceleration. If I give the car any more gas than I usually do, it hesitates before going anywhere. One day I needed to get over on the highway fast and floored it - it took the car about 2 seconds to respond. Then, yesterday, we were turning on to a highway from a side road and I tried to accelerate (gas about 1/2 way to the floor) and it didn't respond at all for about 5 seconds and the "Check Engine" and the traction control lights started flashing at me. We were on a paved road with no gravel, water, ice, etc and the traction control light began flashing on the straight, not while we were turning. There are also days when it feels like there is an anchor tied to the car and it just doesn't want to give me any umph at all.
- Rough starts. This is the really weird one as there is no rhyme or reason as to when it happens. Some times it takes the car several revolutions to turn over. Oddly, it's never on the really cold (under 20 degrees F) days, but it has happened when it is ~35 degrees and a couple of times when I have started it in the middle of the day to grab lunch and it is ~65 degrees out.
- Running rough. This usually happens after a rough start, but can also happen at other times. It just idles very rough and won't calm down. These are the days I have the worst time with the shifting issues.
I had a 2001 Forester that threw a rod, which forced me to get this car. Everyone who has driven both agrees that the 2001 was quicker, easier to drive, and had more gumption than the 2012. It also had less problems even though I purchased it used in 2005 (until the whole rod-throwing thing, of course). I really want to love my 2012 Forester, but I am so upset that, for the first time in my life I have a new car, and it runs terribly.
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Right before Xmas our 09 Forester was hit while parked on the street. The whole front end of our car got wrecked. Was still driveable but we needed a new radiator, AC compressor, fenders, bumper, hood, lights, etc...over 5K worth of work.
As soon as we picked it up we noticed that when you press on the gas the car makes a high pitched whistling noise, almost like the noise when you'd try to tune in an old transistor radio. It only happens when the car is driving and the gas is pressed, not when parked or in neutral.
I know we should have probably brought it right back to the shop that day but I really did not like the shop at all and they are not at all convenient to where I live. I've read it could be a loose cat converter. I checked the air intake housing and that is secure.
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I have a 2002 Subaru Forester L with 178,000 miles on it. I just had the valves adjusted. I have replaced the coil pack, #2 injector, plugs, wires, and throttle position sensor. I have also cleaned the idle air controller. The car only shows sign of a miss when it idles. It gets great gas mileage otherwise. I am at a loss on what to do next as the car doesn't have a MAF sensor, I can't do anything with it.
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The check engine light on my 2006 Subaru Forester with 92,000 miles came on recently. A scan revealed the engine was running lean. After three more trips the mechanic determined the rear O2 sensor was bad and replaced it. This was the only part replaced. Now the computer is sending code P2097; Post Catalyst Fuel Trim System Too Rich Bank 1. I have read it could be anything from the catalytic converter needs replacing to "resetting the adaptation values."
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Got a 98 Subaru Forester with 130,000mi. Good car so far. Just got a good deal on a scanner and it reports 1 code - PO0400. I see it mean EGR flow error. What is the most probable cause or a troubleshoot process to narrow it down? My repair manuals on the car are kind of lacking and I can't even find the blasted EGR valve! I thought I found it but I think it's the knock sensor.
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I took my car to my previous shop for a P0325, Knock Sensor Circuit Malfunction. They wanted nearly $500 to fix it. My new shop said that I just needed some engine treatment and the code went away for a week and a half, but it came back yesterday, and my engine ran a little rough.
I heard what sounded like a very rough engine and it was my car. The technician came in saying that I was only running on two cylinders, but that sounds like far worse of a problem than I had been experiencing. They say that I need a $266.80 valve adjustment, which is all labor, but the total is $300 more than that:
Engine Light diagnostic: $44.99 Shop Fee: 35.00 Tune up package Remove and replace spark plugs: 60.03 Additional access time - remove: 64.20 and replace spark plugs: NGK Spark Plugx4: 9.96 Adjust Valve Clearance: 266.80 Pepguard Limited Extended Labor: 58.65 Warranty BWD Custom fit ignition set: 36.39
Parts: 46.35 Labor: 436.02 Other: 93.65 Tax: 6.55 Total: 582.57
Of course, my roommate, who is upset that I am not continually pouring fluids into leaky power steering and AC systems butted in and said the entire thing is preposterous. Problems with cylinder firing are invariably the result of bad spark plugs andor wires.
Well, they say that I need to replace those, which cost $46.35, the least expensive entry in the entire estimate. They just want to charge $124.23 to replace them.
Why don't I replace them myself and see if that fixes my problems?
They say that if the valve clearance adjustment does not fix the problem then I need new cylinders and valves.
Regretfully, I have a "service plan:""Engine: All internally lubricated parts contained within the engine block, cylinder head(s) or rotary engine housing(s); oil pump; timing belt or chain, timing gears and timing tensioners; water pump; engine block, cylinder barrels, engine head(s), rotor housing(s) if damaged by the failure of an internally lubricated part. Dipstick and tube; harmonic balancer; oil pan; timing chain cover."
I cannot imagine that it would cover a valve clearance adjustment and they would only cover cylinders and valves "if damaged by the failure of an internally lubricated part."
So, ride my bike eight miles tomorrow, replace the spark plugs and wires, and hope that it is enough?
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I have a 2006 Subaru Forester with 95,000 miles on it. Earlier today the CEL (solid) and cruise (flashing) came on while I was driving. I believe it may have occurred as I was accelerating up hill. I filled up yesterday, so I tightened the gas cap when I stopped. On my way home, I stopped by my mechanic and they read the code; P0420 Catalyst Efficiency Below Threshold Bank was the code that was read. They reset the code for me but told me that the catalytic converter is what needs to be replaced.
My question: Could the light coming on be incidental (i.e., is it possible that it was a "blip" and my catalytic converter is okay?)? My mechanic said he thinks it is, and that my car should last me quite a bit longer. I am asking because I've put in a bit of money into the car of late and I'm wondering if I should just jump ship. I should say that the majority of the repairs are maintenance (e.g., brakes, tires).
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My 2000 Forester has 96,000 miles on it. A few months ago, the CEL came on. At first it would turn off every couple of days but would eventually pop back on. I first thought it was tied to putting gas in the car, now I think it was just a coincidence.
Over the past two months, I have replaced the catalytic converter with a aftermarket piece (done by a mom and pop muffler shop) and replaced the front o2 sensor three times. The first two times, I used Bosch sensors from an auto parts store and had the code cleared. After about 50 miles the CEL came back on. Just yesterday, I picked my car up from the dealership where they installed a Subaru fron o2. After about 30 miles, the light is back on again. Code is P0133 - heated oxygen sensor, bank 1 sensor 1, circuit slow response.
Now, the dealership is suggesting I need to replace the catalytic converter with a Subaru converter before they can source the issue.
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At a bit over 43K miles the check engine light came on with a blinking cruise light. Dealer has confirmed that both secondary injection pumps have failed for reasons unknown. I think this is part of the pollution control system.
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2002 Subaru Forester I took my car to the Auto Zone to read a check engine code. It came back as being a "knock sensor". Besides that I needed a battery, and when the guy was putting it in he said my engine was moving too much and that I probably needed motor mounts.
I was looking at a discussion back in 2010 and the Subaru specialist told the person needing motor mounts is rare for a Subaru, is that true? I'm taking it to a mechanic, what should I expect? how many motor mounts does a subaru have?
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I am getting error code po457 Evaporative emissions error, I am told the canister purge valve could be bad.
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I have a 2001 Celica GT and the CEL just came on. Went to Autozone and had the code read (PO420) - they said it could be O2 sensor or bad catalytic converter. Is there any way to narrow it down before I just start buying parts to replace? Car has 140,000+ and runs great...surprisingly one of the few that doesn't seem to burn oil! PO420 diagnosis?
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I own a 2003 VW Jetta GLS 2.0L 4 Cylinder and my CEL recently came on throwing the PO420 code (Catalyst System Efficiency Below Threshold (Bank 1)). So I replaced both the upstream and downstream O2 sensors. Well just one day after replacing the sensors the CEL came back on with the same code. I was wondering weather or not I should replace the whole catalytic converter or if there was anything else I should try. The car runs fine, exactly how it did when I bought it.
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Since 1 year i have this error code in my GX 470. I have replace all oxygen sensor but after 1 day the error code is coming back. How to resolve it ?
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My Subaru was violently shuddering. I think the cold weather has made it worse. It seems to just be when I accelerate. I'm not sure if it's the CV joints or the rack and pinion.
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I have a 2006 Outback XT, which recently started shuddering (like it wants to stall) at idle... At least that's how it started. I noticed it for a few weeks but with no check-engine light, and no error codes cropping up, I kind of ignored it. It then started to stall at idle. Took it to my local guy, who checked all the simple stuff: vacuum hoses, mass air flow sensor, he even removed and cleaned up the throttle body. But the problem persists.
I guess the part that really has me puzzled is the lack of a check-engine light or an error code. With how computer-regulated cars are nowadays, I'm baffled as to how this isn't causing some alarm to go off.
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