I have a 79 with a 5.0 efi out of a 86 crown vic police car. Shorty headers offroad h. I bought it as a carb car and changed it back to efi and it was running great. Then all of the sudden its running rich and popping through the exhaust. Engine lacks power when reving up or driving. I have .4 volts at the ecm at idle for the o2's and my tps, act, cts check out good with multimeter. I changed the map with one I had and no change. Im thinking of going back to carb but rather not.

 

Got it straight finally wire to module hot all the time and not suppose to be so my timing would retard while reving up. and wiring to right bank o2 was pulled out off socket. Running great again.