Cylinder misfire and other probs

[jpruessner]

I am coming here to get help you knowledgeable people. I have a ’98 C1500 2WD with 5.7 liter. The truck 170,000 miles on it. Today I was driving on the highway and went to pass someone and when it downshifted, I hear a loud rattle type noise that went away after acceleration. A few seconds later I noticed my SES light was flashing. At highway speeds I could hardly notice much difference but did feel a little lag.

After exiting the highway, I came to a light and when I was stopping it started to die. I had to give a good amount of gas to keep it from dying and it was sputtering and shaking really bad.

We made it back to town with the same things happening the whole way. I went to straight to Auto Zone and had them run the codes. Here is what I got:

P0101: PCM has determined that there is a discrepancy between the actual MAF input and the calculated MAF input derived from the input gathered from other sensors. The listed probable causes are vacuum hose off, TBI tube loose, BARO/MAP defective, or MAF dirty or defective.

P0307: PCM has determined that a misfire has occurred in cylinder 7. The listed probably causes are the ignition system fault-spark plugs, ignition wires, coil, vacuum leak, injector fault, and high or low fuel pressure.

After seeing these recommendations, tonight I pulled the spark plug for #7 and checked it. It was pretty black, moreso than I expected since I replaced all plugs and wires about 6-8 months ago, however, that plug was no worse than a couple of the other spark plugs I checked. I also checked the wire and it was fine. I also took off the MAF sensor and cleaned the wires with electronics cleaner and put it back on. Neither of these things that I did had any results.

So my question here is what the hell do I do? What suggestions do ya’ll have for me? Thanks a lot.