P0171 CHEVROLET - what is a catalyst mon mean on the obd2 scanner it says its incomplete

Question

I changed all O2 senser and cleaned mass air flow, and still have lean codes for bank 1 and2 come up but obd scanner says all is good except catalyst mon and the evap emission mon are incomplete what do I do next

Answer 1

P0171 Fuel trim lean bank 1

Hows the idle, is there is a misfire or a p0300 (random misfire) P0171 will also code up. To find the P0171 a ijector balance test needs to be performed and also a fuel pressure test needs to be performed. The fuel presssure specification is 55-62 psi at idle, When you read a scan tool the complete and incomplete are monitor readiness test, These are data that is needed for vehicle that will go through a emission test, For the monitors to complete the vehicle must be driven a certain way for a certain amount of time.