k_bo

Hole story:

I have a 95 I6 4.9L with a check egine light on (turns on and off speratically).

I had a guy scan with a computer and got a P0171, and another evp ept voltage low.

I bought and changed the O2 sensor, as well as the canister purge valve (w/new hoses), per advice.

I then figured out how to run the on board EEC-IV using the CIL and got codes:

327 Electronic pressure transducer (EPT)/differential pressure feedback exhaust (DPFE) sensor/electronic vacuum regulator (EVR)
522 Neutral/drive switch (NDS)
512 Keep alive memory (KAM) fault
111 All systems OK

Replaced both battery terminal ends and a new battery.

I've checked EGR Vacuum Solenoid for carbon buildup, but was clean.

I have an oil leak. Its at the top of the motor underneath the intake manifold. Not a large leak but a leak (guessing not the problem).

I have checked all other hoses for a vac leak using a can of starting fluid but all seems fine.



I took the top intake manifold off and wanted to take the bottom half off to replace the gasket but I'm sure how to continue.... removing the injectors mainly. I may be way over my head but if I could be walked through i have confidence I could do it.

Thanks in advance for any help.

justintendo

p0171 means the 02 is reading a lean condition, so its possible that is going on...how does the truck run? what are you going to do with the injectors? any idea what fuel pressure is? sometimes the pressure regulator goes bad allowing too much pressure, but but they can also go bad choking back pressure.