I've got a 2014 Chevy Equinox with new pluigs, coils, fuel injectors, recent top-engine carbon clean, new AC Delco O2 sensors, and relitively new CAT. Getting a P219A-00 for Fuel trim cyliner balance. Any ideas where to start diagnosing? I saw this online as possible causes:
Leaking or contaminated fuel injectors
Low fuel pressure or running out of fuel
Leaking evaporative emission (EVAP) canister purge valve
Exhaust or intake air system leaks
Exhaust gas recirculation (EGR) system
Positive crankcase ventilation (PCV) system is leaking or the valve is stuck open
Ignition system
Incorrectly seated engine oil dipstick, tube or oil fill cap
Just curious if anyone has had this issue with a GMC of Chevy and succesfully diagnosed.