2013 Mustang gt, installed long tube headers with BBK catted x pipe a few months ago, just had the car up on a lift yesterday and noticed the passenger side cat that’s on the x pipe is touching the frame. Plenty of clearance on the drivers side. I will occasionally hear a knock from under the car (which is probably the cat hitting the frame) when cold for a few seconds, then the noise goes away.
I look at the cat and frame and see little white scratches on both where they’re making contact.
Will these making contact eventually put a hole in the cat? Could I wrap the cat so there’s a buffer between it and the frame?
Besides blaming bad product fitment what else can I do to fix this? First pic is fitment on the drivers side, plenty of room. Second pic is fitment on the passenger side. Hard to tell from the picture, but the cat is BARELY touching the frame.
Should I just leave it alone? I only hear the noise at a cold start then it goes away after a few seconds at idle. I don’t hear it when driving, but my exhaust is pretty loud so that could be why too
Loosen everything up, shove and hold, tighten?
2 Likes
If @texases suggestion does not work, visit a performance shop to see if they can heat and bend the pipes just a little bit to add some clearance.
2 Likes
I have tried loosening the midpipe from the headers and pushing it more to the drivers side but it doesn’t stay put
I considered having a shop hammer the cat in a bit.
Probably a dumb question but would it be possible for a shop to move the engine slightly more towards the drivers side like maybe just 1/4 of an inch? The problem stems from the header fitment being slightly off center causing the x pipe to be out of alignment in relation to the frame
NO, don’t! That will destroy the cat.
4 Likes
The part of the pipe that is touching the frame is the cat. If I was running off road x pipe without cats I wouldn’t be having this problem
Would heating and bending the cat be safe for it?
No, do nothing to the cat, I’d have a good shop see what else in the exhaust system could be bent, like @Mustangman said. And I’d skip moving the engine.
Any chance the x pipe is upside down?? lol
Not sure if it is asymmetrical or not…
But as already said, NOOO, do not hit the cats or modify the cats in anyway, and do not move the engine over any, heat and bend the pipes or the header tubes, or use a pipe bender to bend the pipes…
Are the headers BBK also??
I’d try heating the header til cheery red, and then take a Port-A-Power spreader and place it between the frame and the pipe and push the exhaust away until clear.
I’ve had to do some creative stuff like this with some aftermarket exhaust components.
Tester
1 Like
Maybe the exhaust system hangers mounting points can be moved slightly to the side, away from the frame. Elongated holes, etc.
