ryanewing88

i just bought my car not too long ago. I knew it had a baby cam in it but i wasnt sure if the valvetrain had been replaced. about 2 weeks ago, i could hear some ticking, so i replaced the header gaskets. i started the car, that didnt fix it. so we checked the sensors, and along with the obvious O2 sensors being bad, it read a bad knock sensor. i was told to take it home till we could figure something out. when i pulled out of the shop, the car started to backfire.

so...

im thinking, the knock sensor wouldnt go off unless there was a problem near the heads. and it wouldnt backfire unless a lifter was failing. could that be the problem? a colapsed lifter or bent pushrod? what else could it be?

thanks for any help.