I have a 2001 Toyota Corolla and have replaced the upstream and downstream oxygen sensors, cat converter, coils and spark plugs, intake manifold gasket, air filter, MAF sensor and even the gas cap. I no longer have any random misfire codes but still have a P0171 code. I am wits end as to what to replace next can anyone help? Thanks
2001 Corolla Driving Me Nuts
- Thread starter hd2004
- Start date
Don't replace anything ... DIAGNOSE!!!
You are running lean. Given that you have already replaced the upstream sensor and intake manifold gasket, I would check all vacuum lines for a leak using a water bottle or carburetor cleaner. If you verify that there is no vacuum leak, then you may need to check the fuel injectors to make sure they are flowing properly and not plugged up.
Engine running lean is not going to be ignition related, so the problem lies either in air going in after the MAF sensor or fuel delivery issues.
You are running lean. Given that you have already replaced the upstream sensor and intake manifold gasket, I would check all vacuum lines for a leak using a water bottle or carburetor cleaner. If you verify that there is no vacuum leak, then you may need to check the fuel injectors to make sure they are flowing properly and not plugged up.
Engine running lean is not going to be ignition related, so the problem lies either in air going in after the MAF sensor or fuel delivery issues.
Welcome to the Corolla Forum! :thumbup::clap::thumbup1:
:balloon:arty:
Why were all those parts replaced? Were they diagnosed as being worn out?
Don't replace anything. Diagnose.
Google the year/make/model of your car and the trouble code and you will find many websites that will help you diagnose the problem instead of randomly replacing parts, which gets very expensive, time consuming, fills a trash can full of perfectly good parts and your wallet ends up with a big hole in it. Meanwhile, the counter person down at the discount auto parts store who sold you all those unneeded parts gets a big slap on the back and a, "Good job!", from their boss and your car still has problems. :thumbdown:
:balloon:arty:Why were all those parts replaced? Were they diagnosed as being worn out?
Don't replace anything. Diagnose.
Google the year/make/model of your car and the trouble code and you will find many websites that will help you diagnose the problem instead of randomly replacing parts, which gets very expensive, time consuming, fills a trash can full of perfectly good parts and your wallet ends up with a big hole in it. Meanwhile, the counter person down at the discount auto parts store who sold you all those unneeded parts gets a big slap on the back and a, "Good job!", from their boss and your car still has problems. :thumbdown:
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