I have a question about the plastic orifice cap. I recently replaced my pump due to a P0171 and during I found the origice cap to be cracked. My question is will that keep the system from properly pressurizing? I had the P0171 come back once since. But has since not returned. There is the injector style o-ring below that so my hope was it would seal and the plastic cap was more to keep it centered in the orifice. If your opinion is not, would you happen to know a part number for that?
Don't think replacing the fuel pump will fix the P0171 problem. More than likely you have air vacuum leak. Recommend you check all your hoses and pay close attention to the air filter box hose. Also a "lazzy" upstream O2 sensor may trigger the code. Don't believe a cracked cap will cause problems.
Updated on September 18, 2019