P0172, fuel in oil, Rough idle, engine run-on GM
Diagnose and fix P0172, fuel in oil, Rough idle, engine run-on GM
GM has issued a service bulletin #PIP4783B to address P0172, fuel in the oil, Rough idle, engine run-on GM vehicles listed below. Before you perform any diagnostic tests, pull the engine oil dipstick, and check for the presence of fuel. GM has determined that a P0172 System Too Rich (Bank 1) may be caused by a defective high-pressure fuel pump that’s leaking fuel into the crankcase when the plunger is depressed.
GM advises you to isolate the fuel tank fuel pump and perform a leak down test to rule out a pressure loss from the primary fuel pump. If the primary fuel pump holds pressure, perform close off the fuel line to the primary fuel pump, and conduct a leak down test on the high-pressure fuel pump. If the high-pressure fuel pump shows a pressure loss during the leak down test, it must be replaced, along with the fuel inlet hose.
Vehicles affected by #PIP4783B
2010-2012Buick Lacrosse 2.4L engine
2011 Buick Regal 2.4L engine
2012-2017 Buick Verano 2.4L engine
2012-2016 Chevrolet Captiva 2.4L engine
2010-2017Chevrolet Equinox 2.4L engine
2010-2017 GMC Terrain 2.4L engine
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