Can my throttle body gasket be the cause of the P0171 code?

Question

Removed throttle body to do other maintenance but didn't change the gasket.

Answer 1

Hi there,

It could cause this code if it were leaking. Since the code is for a lean fuel mixture only on bank 1 of the engine though, it's not likely. I would suspect either the intake manifold or the front O2 sensor. If the car is running fine the front O2 would be the most likely culprit.