I have a Slp Loud mouth on my car and Ever since I have had it on there has been some viberation at certain RPMs. I installed the PCMforless PCM yesterday and took the car for a spin. I punched her Down and every time the car shifted there was a Very loud BOOM coming from underneath the colum (like some one with a hammer was hitting the frame.)
and last week When I stepped on it my brother said there was some sparks that came from the underneath my car.
WHAT DO YOU GUYS THINK, is it my Exhaust hitting the Frame or is the LOUD BOOM coming from my Transmission mounts coming loose ( same sound came from my buddy's camaro before its transmission basically fell out)
OR IS it both of these.

 

??? dont know for sure, but if you jack the car up, while its cool hit the exhaust with the hand, if it moves see wht, if anything, it hits. as for the trans mount, that will be noticeable if it needs replaced.

my friend has a camaro, and he had to replace his calipers and whatever it is that they mount on because they were causing a loud pop. only way to check is to lift the car and check for bare spots that arent supposed to be there.

 

i would say its probably your i-pipe hitting your crossmember. Mine does it and I am going to tack weld it to hold it so it cant move and virbrate and bounce around. Kinda sounds like the exhaust is hanging on the ground.