Header donut gasket.

[rabies]

ok so suposedly i have an aftermarket header.
my downpipe was a tad leaky and hanger was broke and sitting on crossmemember.

so i bought a new downpipe. didnt come with donut gasket. went to autozone and spent 10 on one for it. didnt fit.
prolly because aftermakert header.

it fit the downpipe though.
after installing anyways. (i had to drive it) it leaks very bad and gives me 02 sensor code. bank 1 sensor 1. terrible idle and bad mpg.
ANDDDJHSIDFHSD it still sits on the crossmember(replaced trans mount same time)

SOOOOOOOOOO. why does it still sit on crossmember? hanger needs bent? the downpipe hangs kinda low.

and what do i do for a donut gasket. no idea what brand header i have.
any DIY donut gasket things?
the outside diameter was fine. inside wasnt. it was too small for header flange.
so i tried grinding it down with dremel. would do a thing.
tried a carbide bit. it ripped the it up since its like an sos pad..

sounds like open downpipe ford f150

cut off header flange and dp flange and just hardmate it together?

[4.3LXJ]

The best thing to do here I think is to go to an exhaust shop and ask them. They have all kinds of stuff so they can work on anybodies stuff. I am sure they will have what you need

[rabies]

they wont....i deleted my cat
they give me a hard time about and shun me

i wish i knew a shop that was like "no cat? whats that have to do with my paycheck?"

[NW99XJ]

If you're legally alowed to not run a cat (former military / live outside emission required county / etc.) ...then they have no room to complain.
I would force the issue if you're in the right.
Now if you deleted your cat "just because" ...then you're prob gonna be SOL.
Your other option would be to go in with measurements, and try to get what you need sight unseen. Might work, might not.....