P0420 PONTIAC -

Question

I have 2004 Pontiac Vibe with codes P0456 and P0420

Answer 1

P0420 Catalytic below efficiency

P0456 Evaporative emission very small leak detected

P0456 when you get a small leak detected this is usually the fas cap, either not tighten or time for a new one due to the fuel cap poor sealing,P0420 this is the catalytic convertor below effieciency, check for a tune up , if the sparkplugs are worn  you can get this code, or even a vacuum ,can cause this code