[maximusppl]

Hello, I've had my FI catback installed for a little while now. On cold starts I hear what sounds like banging/vibrating underneath. I have taken off the rear plastic muffler shield because it looked like it was hitting there, but the noise still persists. It's not a valve type issue, i dont think. Any suggestions?

[pbonsalb]

You really want to spend a few minutes under the car with a light, looking and, where necessary, feeling around the piping to endure adequate clearance to the heat shielding above and to the sides as well as the chassis brace. The aftermarket exhausts are in at least several sections. It is possible to loosen clamps and rotate a section slightly to add clearance for the exhaust sections that have bends. You can also loosen clamps, pull the exhaust down a bit or to a side and then tighten the clamps while holding it in the new position. As a last resort, you can take a pry at or other flat curved tool and gently pudh heat shielding up or to the sides, but don’t bash it or poke holes in it or cut it. Your exhaust is probably just a tiny bit off — the lean running cold start seems to shake the exhaust more than it moves when driving the car.

[Pilatus]

Check the the exhaust flaps, they are known to vibrate and rattle at startup

[pbonsalb]

The OP wrote that he does not think the issue is the exhaust valves. He could test by unplugging the harness from the motors while the valves are open, unplugging and listening for rattle during the next cold start.

[Pilatus]

Originally Posted by pbonsalb

The OP wrote that he does not think the issue is the exhaust valves. He could test by unplugging the harness from the motors while the valves are open, unplugging and listening for rattle during the next cold start.

Agreed. I would still test as you suggest to rule out 100% given that it only takes a few minutes to do

[maximusppl]

It's not necessarily a rattle (like a stone inside of a pipe) type sound. More sounds like its banging/hitting...if that makes sense. Will have a shop check on friday am as there is snow on the ground here right now and I dont have access to a lift.

[Pilatus]

Originally Posted by maximusppl

It's not necessarily a rattle (like a stone inside of a pipe) type sound. More sounds like its banging/hitting...if that makes sense. Will have a shop check on friday am as there is snow on the ground here right now and I dont have access to a lift.

Good luck. Keep us updated!

[bxdinster]

I have an fi exhaust and it seems to be extremely difficult to get this exhaust to sit right the main problem seems to be that it sits lower in the tunnel. I bet it is touching the factory x brace in the center of the car.. If you adjust it, it will sometimes settle back down and hit it again this is what Fi sent me when i complained about it.

[pbonsalb]

The picture quality is poor, at least when viewed on my phone, but it looks to me like the exhaust is too close to the passenger side just before the X. I would loosen the clamps at the front end, at the downpipes, as well as the other clamps and try to adjust to center it. Initially, I would try fully seating the exhaust into the downpipes. Fully seating or pulling out a tiny bit can affect clearance to the cross brace as well. You can also try pushing upwards as you tighten clamps and may succeed in raising it a little. The circled sections might also be rotated slightly to lift the exhaust up a little since those sections have a slight bend. Twist them and you should see a little movement and then tighten.