the other day i put jdm 4-1 oem headers on my car and i took the car to a muffler shop to have them put on my carsound cat and dunk exhaust and flexpipe... now the check engine light is on because they didnt weld on a spot for the second o2 sensor so im goin to bring it back.. but what i noticed when i went under the car was that the headers were bolted to the flexpipe, flexpipe was bolted to the cat, but the cat was welded to the rest of the exhaust is that normal??? or should it be bolted to the exhaust?>???

 

If there was no flange for the cat to mount then yea. If you wanted it bolted you could have told them to weld on a flange. Its not hurting anything.

 

Usually there is a 3 bolt flange on the back that connects the cat to the b pipe. I can't speak for the carsound unit, but the OEM and my Random Tech cat had the bolts. If you have to change either the cat or the b pipe it will be harder now. Need a blow torch..... (hmmmm FIRE! uhhh cool)