Code P0171 for 1999 Lexus RX 300
09-24-13, 07:49 AM
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Code P0171 for 1999 Lexus RX 300
1999 Lexus RX 300. The check engine light came on. We diagnosed with code P0171 for too lean bank 1. We did clean the MAF sensor but the problem is still there. We also smell too much gas. I believe it does not burn all gas. However, the engine run strong and smooth. No rough idle or crap. I don't know what to do next. Any of your advices are very much appreciated.
09-24-13, 08:29 AM
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Use the search function. It's been dicussed before. Welcome to Club Lexus
http://www.obd-codes.com/p0171
Info from the link above:
A lot of times, cleaning the MAF sensor and finding/fixing vacuum leaks fix the problem. If you're on a tight budget, start there, but that may not be the fix for certain. So, possible solutions include:
Clean the MAF sensor. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
Inspect all vacuum and PCV hoses, replace/repair as required
Inspect all hoses and connections in the air intake system
Inspect and/or test the intake manifold gaskets for leakage
Check for a dirty fuel filter and proper fuel pressure
Ideally you'll want to monitor short and long term fuel trims using an advanced scan tool
If you have access, you may want to run a smoke test
http://www.obd-codes.com/p0171
Info from the link above:
A lot of times, cleaning the MAF sensor and finding/fixing vacuum leaks fix the problem. If you're on a tight budget, start there, but that may not be the fix for certain. So, possible solutions include:
Clean the MAF sensor. Consult your service manual for it's location if you need help. I find it's best to take it off and spray it with electronics cleaner or brake cleaner. Make sure you are careful not to damage the MAF sensor, and make sure it's dry before reinstalling
Inspect all vacuum and PCV hoses, replace/repair as required
Inspect all hoses and connections in the air intake system
Inspect and/or test the intake manifold gaskets for leakage
Check for a dirty fuel filter and proper fuel pressure
Ideally you'll want to monitor short and long term fuel trims using an advanced scan tool
If you have access, you may want to run a smoke test
1999 Lexus RX 300. The check engine light came on. We diagnosed with code P0171 for too lean bank 1. We did clean the MAF sensor but the problem is still there. We also smell too much gas. I believe it does not burn all gas. However, the engine run strong and smooth. No rough idle or crap. I don't know what to do next. Any of your advices are very much appreciated.
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