P0171 2007 Toyota Corolla -

Question

My check engine light came on today and a diagnostic check revealed cod PO171 lean mix.

I used CAC MAF sensor cleaner and put the sensor back in place after it was dry.

How long before the check engine light should go off? Is it determined by number of drive cycles or number of miles driven?

I had this happen once before and cannot remember how long it took before my light went off.

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Answer 1

P0171 Fuel trim lean Bank 1

If the ECM does not see a problem the CK ENG LT should clear at the 3rd drive cycle. This also depends of what caused the code condition, Is there any other code that are present? If the vehicle is less than 80,000 mile there is a warranty to reprogram the ECM. TSB# EG006-05