Purge / Rich / LTFT ?s - Equinox 2.4

[Boost]

'10 Equinox 2.4 has a current P0172 (rich) and running rough with LTFT at around -35. Also has misfire codes, passed and failed and history but that is related to the excess fueling in my opinion. All the other readings seem fine (MAP /MAF / TP) and I checked for vacuum leaks including the filler neck and dipstick area.

When I reset the fuel trims, it runs perfect for a few seconds before it goes rich again (!).

One thing I noticed is the Commanded EVAP purge is 11% at all times at idle. Not sure if this is normal, I know it runs tests but even after the Evap Purge test status is complete and ok, it still commands the purge to 11-12%, and increases with revs. Not knowing what else to do, I blocked off the Purge to the engine. When I reset the trims, it did not return to as rich as before (around -29, -28). Reset the trims again, and once more, it improves the LTFT it settles on ( low -20s ). A few more times and we are within normal range (-15 or so ).

?????

One thing I plan on is comparing a similar vehicle if I get a chance today for the commanded purge at idle, as well as the trims. Please give me your input / thoughts on this! Thanks!!!

[Boost]

Also, the alcohol content shows 0% in the scan tool.

[joecar]

List all the DTC's you see.

Check that the inside of the FPR reference hose is not wet with fuel.

[Boost]

Thanks Joe. The vehicle had P0172 current and some misfire codes, I let it go a few days ago with a new purge valve and an updated factory re-flash and it has not come back. It seemed to run much better after re-setting the LTFT several times. Those 2.4 DI seem to have a few teething problems... Thanks for your time anyway! I hope to try to learn from every vehicle!