2003 Lincoln Navigator 4WD 5.4L Engine P0172, P0174, P2196 - Slow Response Below 30mph After Transmission Replacement
My 2003 Lincoln Navigator with 4WD and a 5.4L V8 engine is experiencing slow acceleration, only responding up to 30 mph. The transmission was recently replaced, but the issue persists. Diagnostic trouble codes P0172 (Rich mixture detected in Bank 2), P0174 (Rich mixture detected in Bank 1), and P2196 (Fuel trim malfunction) are present. I'm seeking advice on how to diagnose and resolve these issues. Any insights into fuel system problems, sensor failures, or injector performance would be greatly appreciated.
This appears to be a fueling-related issue. Begin by checking the injectors in Bank 1 (passenger side). Perform a fuel pressure leak-down test while the engine is off (KOEO) to identify any leaks. Also, remove the spark plugs and inspect them for wetness or signs of black or tan deposits—this can indicate rich combustion or clogged fuel injectors. Remember, Bank 1 refers to the passenger-side cylinders.