em1gangsta

ok, so my car is throwing the PO172 code which means its running too rich. but now it has a pending code for PO170. and it says fuel trim malfunction? the only thing i have on my car is the J's racing intake, 4-1 headers and exhaust. why would this happen? its not a code yet, but what could i do to fix it? i dont have a V-AFC either, and its ODB2. i dont really know what to do? any suggestions?

em1gangsta

no one has an answer?

redej878

Have you checked fuel pressure?? also what model and year??

wrenchez81

the ecu watches ur o2 sensor input to manage your fuel trim.. put a scanner on the car, go to datastream,, and monitor the signal.....

wrenchez81

ALL DATA lists the possible causes as:

1. fuel pressure regulator
2. fuel return pipe clogged
3. fuel injector leaking
4. primary (upstream) h02s deteriorated
5. MAP sensor performance
6. EGR insufficient flow
7. EVAP purge valve leaking
8. valve clearance


due to the lack of any other codes i would start with the upstream sensor FIRST!!!

gsrhatch2356

Well this is a good little list but there are still other things that could still cause a rich condition and as far as the fuel trim malfunction code. all that means is that it is maxed out and still cant correct the condition so. something like this will require a scan tool and basic knowlage of engine diagnostics. you may find something with the fpr but otherwise I would get a scan tool and go that route.

Evs-One

P0170 is just a general DTC that is stored before the actual DTC- P0172.

When Short Term Fuel Trim falls below .85(85% fuel delivery of normal), than a P0172 code is thrown.

I usually find either a problem with ECT(Engine Coolant Temp sensor output) or incorrect valve lash. It could be faulty ignition tune parts, O2 sensor, etc.

em1gangsta

wow. thats a lot of things that it could be. so should i get a scanner diagnostic tool and run it to see how everthing is running? Becuase i have one of thse that my friend gave me. so ima do that first? any other suggestions?