Quote Originally Posted by Six_Shooter View Post
I suggest that he check the plugs and the cylinders when he got a chance and see if he finds anything. Sure enough, cyl #5 has issues. He fixes that, then the tune is way out. We went out last night, and I tuned the car all over again, and it's a whole different animal now. So make sure that what you are tuning has no mechanical issues. Even a new build does not guarantee that the engine is perfect. ;)
Had a cracked plug on a F-body. It does mess things up. It seemed to be running OK except that it seemed a little flat.