P0171 Cadillac -

Question

code p0171 and p0174 on a 2003 escalade. the engine will not idle. runs but will soon stall. changed fuel filter and air cleaner plus plugs and wires. will a O2 sensor lean out the mixture enough to stall the motor? or should I inspect for a intake leak?

Answer 1

Hi there

You need to check for intake leaks, low fuel pressure and a bad mass air flow sensor. These affect both banks. The O2 sensor can cause the codes, but not on both banks like this.