P0171 2000 Toyota Corolla -

Question

Cleaned MAF, reset light. Light stayed off for 4 weeks is now back with same code. .???

Answer 1

P0171 Fuel trim lean Bank 1

Check for vacuum leak especially at the MAF air duct tube.

Here is a MAF air duct tube that had a rip at the bottom from the MAF to the throttle body , it caused a P0171 and vehicle also stumbled on acceleration.