1995 Firebird Dead skip # 4 cylinder

[Dudley04401]

I need help. I purchased a 1995 Trans Am lt1, and have been messing arond wih a pretty good skip for a while now. The car runs very rich and as a lack of power. Heres what I and a friend have done:

- New plugs
- New wires
- cap and rotor
- coil
- new pcm with lt4 knock module

The car has been scanned by a local gm garage and found a history code dtc 18, the # 4 injector was believed to be inop. ( i think this was jus a history cod from me and a friend unplugging injectors looking for a change in performance) I noided out each injector and harness and had signal on each. Each injector ohmed out at 12.9. So i swapped the # 4 injector with the # 3 to verify bad injector, cleared the codes, and brought back to gm, the # 4 cylinder is still a dead skip. I had a friend bring my car with him today to work so he can check the # 4 plug and wire, from there I am scared I may have to do a compression check..... Ughhh unsure what else to do and looking for any help or suggestions I can get.... The car is pretty much stock only add ons is the lt4 knock module and a performance muffler, it just turned 60k miles, I think the cat has been hollowed by the previous owner... (didnt want false knock so thats why I added the module.... Every thing else looked good on the scanner just the # 4 cylinder.....

[Injuneer]

How did the dealer determine specifically that it was #4 with the misfire?

[Dudley04401]

He used I believe a tech 2 and manually went and shut off injectors, and was also able to see that cylinder not firing with the scan tool? Some news today I found two of my wires #4 being one of them cut, not all the way through but enough to disrupt proper spark, from riding on the idler pulley, I ordered a new set an will put it in on Thursday, hopefully its that simple. Would this cause my car to run really rich? I hope this does it and also hope to notice a big diference, granted I have only been running on 7 cylinders but I cant imagine its been like that the whole time. The power thus far has been dissapointing, hopefully when straightened out there is a big difference. I will post results right after I replace them.

[Injuneer]

Misfires cause the engine to run very rich, at least on the bank with the misfire. The unused air flows out the exhaust, and makes the O2 sensor think the engine is running very lean. The PCM starts adding fuel to that bank of the engine, which it really doesn't need. The plugs in the 3 cylinders that are still firing may start fouling, and in severe cases you may be running so rich the excess fuel is washing the lubrication of the cylinder walls, possibly damaging the rings and diluting the oil. Check your plugs for signs of carbon buildup. Check the oil for a strong smell of gasoline.

[Dudley04401]

Ok. Will do thank you. Sounds like an oil change wouldnt be a bad idea.