[Jcwoodhit]

Originally Posted by bishopts

Compression test would definitely get you some useful information on a direction to go.

Look at your fuel pressure and regulator command percentage.
Ive done a good amount of high pressure fuel pumps. Sometimes they run fine and just have rich codes. On those if you change the oil the fuel trims will be good for a little while. The pumps leak fuel into the oil and the pcv pulls the fuel vapors in and ends up running rich.

I thought the SAME thing, so I slapped in a brand new HPFP and injectors, new plugs and wires, new maf and map sensors, new coolant temp sensor and thermostat, new pcv, new o2 sensors, new vacuum lines, had cats inspected, checked for vacuum leaks and exhaust leaks lmao