Tahoe started running rough this weekend. Last night the CE light came on and coded for #7misfire. I swapped out the coil pack with #1 and reset the light. This afternoon the CE light came back on, again misfire #7. Is this a spark plug and wire issue or is there something else I can check?

All wires and plugs were changed less than 25k miles.

 

I would walk all three items to the opposite side of the engine.... but yes it could be a plug and or wire....might try running some injector cleaner thru also..
did you replace them with OEM or aftermarket plugs wires?

 

yes, thanks

 

replaced #7 spark plug and let it idle for about 5 mins. so far no misfire. This is what the old spark plug looked like after 23k miles. Is this caused by excessive oil consumption?

 

Looks like detonation
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