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?>???

 

I have a 95 honda accord and just put some DC headers on my car last weekend and installed them myself and yes, the headers are supposed to be bolted on to the flexpipe and the flexpipe bolted to the cat, and the cat WELDED to the exhaust. I think your porblem lies within the welding job that the auto shop did. there shouldn't be anything wrong with the header/bolt setup.

 

i was just curious about the welding of the exhaust to teh cat

 

The JDM header is a different length than a USDM header, so the cat didn't match up with the exhaust, like it would've with a USDM header, they probably cut and welded to make up the size differences,
JDM because it's JDM

Your CEL will be gone when the other O2 sensor comes back