Hello and good evening VS!
So I have a question for you smart folks: Is it possible that running orange injectors (rather than the whites) on a T5 ECU in a GLT motor could cause a recurring P0172 code?
P0172 comes up as system too rich bank 1 on my scanner, yet everyone says to look for a vacuum leak as if it were a lean condition. And when I view the fuel trims the LTFT is between 12 and 25%. This leads me to believe the P0172 actually indicates a lean condition in the engine and the ECU is running as rich as it can to compensate. My STFT varies between -5% and +15% most of the time.
Now I have been over the engine bay with a flashlight, stethoscope, mirrors, etc....and have checked all vac lines ( yes the elbow on the side of the manifold too, all new PCV lines), all are tight and secured with clamps or zipties. My vacuum readings on the boost gauge are 24inhg at warm idle in park, good solid idle too so I really don't think it's a vacuum leak.
As far as I know the MAF is fine and the O2 sensor in working order.
The other option would be for a fueling deficit, either clogged filter or injectors, filter is brand new, good pressure from the pump. But here's the thing, this started shortly after I swapped out the white fuel injectors for the stock orange ones as I am sending the whites out to be cleaned. Only running the stock T5 map boost for now, no more MBC till the whites get back.
Is it that simple, is the ECU adding fuel because the oranges flow less than the whites in a given pulse? Isn't this basically the same as having clogged injectors??
Let me know if you think this could be the case. Or what am I missing.