what size is the oem exhaust?

[M20power93]

My exhaust is basically all rusted out so i need a new one. What's the oem size exhaust? It's a 325i m20 motor

[ill4noreason]

I know that it is 1 3/4 from the cat back on dual exhaust setup. Not sure if you have single. From manifold back I am not sure.

[nando]

it's closer to 1 5/8

[devon.818]

i just cut my muffler off and used 1 3/4 pipes with these flared ends to slide over the 1 3/4 stock exhaust pipes.

so yeah, actually diameter is 1 5/8.
simple answer, go to muffler shop, let them figure it out :P

[E30RedtopSR]

i just cut my muffler off and used 1 3/4 pipes with these flared ends to slide over the 1 3/4 stock exhaust pipes.

so yeah, actually diameter is 1 5/8.
simple answer, go to muffler shop, let them figure it out :P

Thats almost big enough for a 120 hp engine.