Spark Plug Change Misfire

[RotaryMachineRx]

Changed all of the spark plugs and wires on my 2012 Tahoe. I removed one spark plug at a time, hand tightened all plugs in then tightened with a ratchet/socket. Popped all wires back on ensuring to hear a nice click. Now I am getting a very rough idle and a CEL on my dash (solid, not flashing CEL)....... is there something I am missing with the tahoe that could cause this? I've changed plugs and wires on many different vehicles and have never had a problem before....... any suggestions?? I've pulled the plugs and wires multiple times and replaced to see if this would help but the problem persists. It was running perfectly fine with the old plugs/wires.

Please help!

PS used stock AC delco wires and NGK TR5IX spark plugs gapped to .040". Also did not use any thread sealant/anti-seize on the plug threads but I doubt that is causing my issue.

 

[sumo]

Have you pulled codes? Be easier to diag if we know what's causing the cel . Also make sure the wires are plugged onto the coils properly.

 

[RotaryMachineRx]

Well I'm going to chalk it up to a bad spark plug. I ended up pulling plugs out one at a time and swapping the old plugs back in. Ended up finding the plug on the third attempt. I can't see anything visibly wrong with the plug (no cracks, tip in good condition) but as soon as I swapped that one out with the old the truck ran perfectly fine again.

 

[RotaryMachineRx]

Have you pulled codes? Be easier to diag if we know what's causing the cel . Also make sure the wires are plugged onto the coils properly.

Unfortunately I don't have an OBD2 reader for this vehicle as it is pretty much completely stock apart from exterior mods.

 

[kbuskill]

I would suggest running AC Delco plugs in a GM.... NGKs are great for what they were designed for... Japanese vehicles.

 

[RED TAHOE LS]

Jesse, Ken made a good point, use ONLY ac delco plugs. I had a similar problem with my Honda using a NON ngk plug, it ran fine until I put it in a hard uphill climb and it shuttered. NGK plugs cured the problem.
Glad you stuck with it in process of elimination to find it, job well done.
David g........

 

[ivin74]

One of your plugs crack while tightening them, now go back and remove one at a time and inspect them real good, this same problem happened to me when i changed my plugs