Recently I had a problem on my protege where a spark plug blew out of the head, and stripped the threads. Normally I would have gone back to the shop where we got the plugs changed to yell at them, except this time around it was me--and it seems that in changing the plugs a few months ago I must've cross threaded the #2 plug.

Anyways, the resulting mayhem burned some wires and destroyed the #2,3 coil and #2 boot. the shop helicoiled #2 cylinder head and replaced (I think) all four plugs. They said they were using NGK or Denso plugs so I'm not concerned really about crap plugs.

I replaced the #2,3 coil and all the wires and COP boots, and the car is running nicely without any noises or strange behaviors, but it feels like it's running at about 75% power. I'm having trouble getting up hills in second, which doesn't feel normal to me.

Could the plug gaps be wrong? I'm hesitant to take out all the plugs right now considering my botched job last time, but I'm not sure what else it could be. The car was fine up until the point when it wasn't fine, i.e when it blew up. Thanks in advance for any suggestions