Check Engine Light - 97 C/K 5.0 L

[johnbu]

My check engine light is flashing...upon checking the codes at Autozone two problems were listed:
1. Cylinder 7 misfire
2. O2 sensor

Unfortunately, the guy at autozone was in a hurry so he checked the codes and reset them and had to run. I did not have a chance to write them down. However, I decided to perform a tune-up ..plugs, cap, and rotor...now I am left with just:

1. Cylinder 7 misfire....

I did check the plug wires...they look good and they boots are still securely fastened.

Any ideas?
Does anyone know of a computer program and cable that can be installed on a PC to read OBDII codes?

Any help is appreciated.

[RABarrett]

The misfire code can set the O2 code. Check carefully the misfire, and make sure it is fixed before going for the O2 sensor. A misfire will cause extra O2 in the exhaust, confusing the system into thinking the O2 is the culprit. Ray

[johnbu]

Originally Posted by RABarrett

The misfire code can set the O2 code. Check carefully the misfire, and make sure it is fixed before going for the O2 sensor. A misfire will cause extra O2 in the exhaust, confusing the system into thinking the O2 is the culprit. Ray

You are correct. Upon performing a tune-up the 02 code went away.
Now I am left with the Cylinder 7 misfire code. Any ideas?

[nusch]

Have you tried running any injector cleaner through? The injector for cylinder 7 might be a little dirty.

[johnbu]

Originally Posted by nusch

Have you tried running any injector cleaner through? The injector for cylinder 7 might be a little dirty.

I did try injector cleaner and I just replaced the #7 plug wire and had the same results - cylinder 7 misfire.

[nusch]

The only thing I can think of except for what you have already replaced would be a leaking or broken pintle valve inside the injector. That would mean you would have to replace that one injector, but hopefully someone else might have a better idea of what it might be or what you could do.

[borninski]

Switch the plug wire around with one of similar length to a different cylinder and see if the misfire travels to the other cylinder.
After working at an auto shop/State Inspection Station for a while I have never seen a case where a misfire could not be remedied with a full tune-up. Whenever we see someone fail an inspection due to a misfire we always recommend spark plugs, spark plug wires, distributor cap and rotor replace and sometimes new PCV. Like I said, I have yet to see someone still have a misfire after a complete tune-up.