Went to the dyno last weekend and we were unable to get a reading. Whenever he went WOT the tach on his dyno would bounce all over the place and shut off. If we rolled into it it would only register to 4.5k.

He suggested there may be a loose ground since he could not get a good reading from any location he tried, crank, coils, etc....

Has anybody had this problem and had it fixed? There were 2 other cobalts there and they read just fine, the only difference was I had an 05 SS/SC and theirs were an 06 SS/SC.

I'm gonna start checking the grounds but wanted a good place to start searching......