P0171 2003 Toyota Corolla -

Question

One Mechanic replaced the MAF sensor two times in three years, a new Mechanic (Pep Boys) can not figure out the problem and suggested I take my car to Toyota. Has anyone had this issue?

Answer 1

Lean means there is to much air. I would start by checking for intake leaks and exhaust leaks

you can check fuel pressure (see specs below)

Oxygen sensors should also be checked (bank 1 sensor 1)