2004 5.3 flex fuel chevy suburban
Cylinder 4 misfire with lean right bank code. Idles great. Runs rough when given throttle. List of parts we have replaced to try to solve issues : Intake manifold gasket, full throttle body assembly, 2 brand new catalytic converters, all coils, all fuel injectors, crank sensor, camshaft sensor, map sensor, all O2 sensors, spark plugs, spark plug wires, fuel pump, fuel filter, pcv and mass air flow sensor. Cleaned and tightened all grounds. And no, swaping the coil and fuel injector to a different cylinder did not move the problem. Can not find any vacuum leaks. Compression tested all valves. All are good. What are we missing? New wiring harness? Computer? We are at our wits end with this thing.