P0171 Mercedes-Benz - how do i fix this on my own

Question

P0171 on Merc 2004 how do i fix this on my own

Answer 1

HI there

This code is for a lean fuel mixture condition on bank 1. This usually is a result of a bad front O2 sensor on bank 1 or a vacuum leak on that bank of the engine. It can also appear if you have an exhaust leak on bank 1.