P0171 Toyota - 2008

Question

my check engine light has been on for 2 weeks now, i replaced the o2 sensors and the MAF sensor, what else should i investigate with my engine I dont want to do more damage to my engine..
Also when stopped at a red light my car shakes and theres a knocking sounds when accelerating in cold weather??
Thank you

Answer 1

P0171 Fuel trim lean Bank 1

Is there any misfire with this code codition? Lean code are usually caused by vacuum leaks that upset the air to fuel ratio. There are 2 popular causes for this code that Toyota has produced. There is a ECM recall TSB # SC-AOJ-PH2 and there is also a TSB about the lean code condition which has a misfire condition because of the lean condition and in sub freezing temperatue TSB # EGO45-07 or CAN-TSB2909 Both of these are dealing with the ECM as being the replacement.