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?
View 14 RepliesI have a 2004 Elantra and I have purchased two different code readers. They were the OBII cheaper readers. One of the readers goes through on the screen what appears to be a diagnostic routine and comes back to the home screen. The other says it has a link error. When we go to OReilly's they say no code comes up. The CEL is on. I want to know if I am missing something simple? I just want the code to get to troubleshooting the CEL light. I have removed the negative terminal and the code goes away for about a week or more then comes back. The only other light on is the air bag light but it has always been on and the CEL has not been on until lately. I have to address all the issues but this is my top one now.
View 7 RepliesI 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.
View 22 RepliesI 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?
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 ?
View 14 RepliesMy 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.
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....
View 4 RepliesI have a 2001 Chevrolet Prizm with check engine light showing PO420 and PO446 codes, what could be the problem?
View 1 RepliesWhile driving home my cel came on, the next morning I took it to the dealership. The code read camshaft sensor. The mechanic ask how the van was driving, I said perfect, no issues no nothing. He said that was kind of surprising.
The next morning went out and no cel at all and van still running fine. Spoke with another mechanic who said a number of things can cause that code and to hold off on the new sensor and see what happens over the next few weeks engine performance wise and if CEL comes back on.
What should I do? Car is a 2002 KIA Sedona mini van that has had zero engine issues while I have owned it since 2010.
2003 1.8t passat wagon. 50k miles... The check engine light came on today. Oil and engine temp are fine. Can most shops plug in and diagnose? Can I get one of those code readers at Advanced Auto parts to read the error code?
View 5 RepliesGetting "Maintenance Required" on Display ... How to Read the Code and diagnose? Is this just a oil change or what? I wish the technology car was more technical. Wish it would actually tell me what the prob was. I have a 2012 Prius 3....
View 4 Replies I recently bought my 2010 gti used with 62k miles on it about 3weeks ago. The car had an carbonio intake stage 1 and a stage 1 tune from Apr when I had bought it. On the test drive and for the first two weeks I had it I did not have any problems. A few days ago on a cold start my car threw an MIL and it was flashing. When I got to school I plugged it into the obd2 scanner. Code read P0303: misfire cylinder 3 detected.
My teacher and I went over possibilities of the misfire. Coil pack, plugs , injector, valve float( even tho this should not occur at 1300rpm cold start) we also thought that maybe because the car is direct injection the valve was not closing all the way due to carbon build up on the top of my valves which in this case I'm glad I don't have an interference head. I moved around the coil packs. What is the cause of this? I'm only misfiring at start and when the engine isn't warms up to operating temp.
I just picked up a 06 XLT 4.0L with 125K that was a bank repo. After 15 minutes of driving the CEL light came on and the code read at local parts counter was 0402 which they said was the EGR system/valve. Is this a common thing? What are solutions (cleaning or replace)?
View 1 RepliesStarted as I was warming up the truck,a slight vibration/shudder. First thing that came to mind was F150. Torqued words of wisdom that it might come back, I had a p0301 before. Had no CEL, so decided to drive it to see if it got worse. Turned onto the main road and on came the CEL. Pulled into my FORD dealer, told him about my problem. Code P0308 misfire on #8cylinder was the read out, COP was done and the plug. 40 min of labor. She's even quieter than when #1 got changed.
View 3 Replies2010 f150 with 5.4 catalytic converter. Engine light has been going on and off for the past couple of months. Had the code read and its says bank one catalytic converter. Ford dealer said to replace the 02 sensors. Had that done but light still comes on and off with same code. Could there be something wrong with the sensor or should I just have the CC replaced also. I just don't understand why it would come on for a few days and then not come on for a few days if its the CC?
View 1 RepliesMy 1999 super duty v10 has thrown a code but my scanner and a mechanics scanner won't power up and read the code, I also noticed that the cigarette lighter is dead. Which fuse controls both the plug and the lighter?
View 3 RepliesBought a Mk4 1.8T gti last year had only about 75,000 on it and drove it for about 10,000 miles. The check engine light went on about 2 months ago and the code read 3rd gear incorrect ratio. It still rode fine until about a week ago when it started slipping. Brought it to the local transmission guys in my town and got a quote at about $3,000-$3,500 to have the transmission rebuilt. The transmission is a tiptronic automatic 6-speed.
View 1 RepliesHere is my situation. A month or so ago when it got cold out consistently I got a rough idle after start up.. CEL. Code read P0355, cylinder 5 misfire. Removed plug to check it. All was good, I put everything back together (anti seize, dielectric greased) So I replaced coil. It went away. This week got very cold and Code P0355 and flashing CEL. Drove for a mile or so and it went away. So I'm thinking vacuum leak, Intake gasket, egr valve or warped intake manifold?
View 11 RepliesI recently purchased an 06 f150 fx4 5.4L with 60K miles. Just recently my check engine light came on and I've noticed a slight rough idle in park. I took it to autozone and the code read P0422 evap emission leak. Bought a new fuel cap but didn't work... EGR valve?
View 2 RepliesI have a 2001 F350 and the temp read-out on the mirror hasn't worked since I got the truck in 2004. Where the sensor is. I found a connector on the back side the core support on the driver's side that has nothing plugged in. Could this be where it should be?
View 4 RepliesI got a 2001 Escape XLT (V6) a couple of months ago. Its in great condition, only 82k miles on it too. It had the notorious door handle issues which I have had fixed. It also had the wet weather stuttering problem, which I had fixed by having all 6 spark plugs replaced (Motorcraft OEM plugs), the back 3 coils replaced, upper intake gaskets replaced, Valve cover gasket replaced, PCV valve replaced (motorcraft).
It runs great when its warm, the problem I am having is when its cold outside and the engine is cold, it starts up fine but idles like crap and if its really cold outside, it starts and dies 3 or 4 times before it can even get to the crappy, stuttering idle. I have to intermittently feed it gas to keep the cold idle going long enough (3 or 4 minutes) before I can drive it. Once the engine is warm it drives like a champ. The only warm engine issue, is occasionally after driving it and putting it in park, the engine will rev up to 2000, 3000+ rpms, and just keep going up until I shut the engine off.
The codes read P0171 and P0174, which are lean on bank 1 and bank 2. It had also thrown a misfire on cyl 6 but once I cleared that it hasn't come back, just the lean codes are still present.
From what Ive been reading, this can be a number of issues, ranging from the IAC valve, EGR valve, MAF or the lower intake gaskets. I'm very much a rookie when it comes to car mechanics, but I think I can handle changing the IAC, EGR and MAF since they are all on top of the engine. However I don't know if I could handle the lower intake gaskets. Ironically, the gaskets are the cheapest part, but the most labor if I paid someone else to do it.
If I replace the EGR, do I also need to replace the EGR Modulator as well? Looking for brand names that are best bang for the buck when it comes to these other parts I have mentioned?