[Jmk91]

Hey guys so I have an issue and it’s driving me nuts. My car definitely smells like it has an exhaust leak after installing my JDL header. I installed the header and the next day I had a 13.5 hour trip. I could definitely smell exhaust fumes inside my car. A little after 4 hours into my trip I stopped at a shop and I had them take a look. They said everything looks great and I could do a smoke test for 90 bucks. I said yeah let’s do it... it passed the smoke test with no leaks anywhere. Guy at shop said it could be the anti seize I am smelling and cleaned my header of the little bit I got on it. Well I’m chugging along all on the interstate and when I wide open throttle I can definitely smell it. I froze my ass off with windows down because I definitely got a headache from the fumes. This isn’t my first header install on a car. I’ve never had this issue before. I know the header has a cat but almost every single manifold I’ve replaced was catted and I swapped it out with a cat less header without ever smelling the exhaust inside the car. The other day I went to start my car outside to let it warm up with windows up. Mind you this is outside not in a garage and when I got into my car it smelled awful.
The header is JDL ceramic coated header I bought it new, also installed grimspeed gaskets. I torqued everything to spec and I did the heat cycle and torqued it down again. Only other mods are a greddy cat back exhaust but I had it prior to header and never smelled anything. A Perrin inlet tube and K&N filter but once again never smelled anything till after the header install. I also upgraded from oft v1 to v2+ tune. I know you’ll get a little smell from taking a cat off but not enough to smell it inside your damn car when you idle it for 5 mins with windows down. Any advice would be greatly appreciated. Because I’m lost and if I can’t figure it out I’m swapping back to the original manifold and selling the headers.