2006 Grand Prix GT - No mods
My wife was driving merging onto the interstate yesterday and had car troubles. She called me and stated she wasn't able to get above 45 MPH or so, and that the CEL kept blinking. I've seen it blink a few times then go off a few weeks prior, so I decided to change the plugs and wires yesterday. There were Iridium plugs in the car and one of the plugs was not in good shape. The ground was completely bent and touching the electrode. I figured that was the cause of the problems, so I finished installing the new Autolite Copper plugs, and took it for a test drive on the interstate and around town. All seemed well. On my morning commute to work I noticed a severe lack of power when accelerating, and my engine was misfiring. Once I got off the highway, I noticed a fast tapping sound which would increase and decrease in speed, depending on RPM's.
I know enough about cars to know that is not a good sound, and it wasn't there the day before. I'm assuming a piston slapped the plug which is why it was bent...Am I looking at a costly repair?
