Cat question

[Ceeker]

Are the cats interchangeable between models and years?

[SmokeE30]

For the most part yes, just watch out for e cars use a single exhaust while I cars use dual so the cat back section must match but manifolds for both mate up. Also the mounting brackets are slightly different depending on auto or manual trans but I have an auto exhaust on my manual car with no issues

[DetailAddict]

i have a complete system off an 87 325e and recently mounted on an 89 325i to pass smog and it did. We did have to extend the O2 sensor a bit.

Leo

For the most part yes, just watch out for e cars use a single exhaust while I cars use dual so the cat back section must match but manifolds for both mate up. Also the mounting brackets are slightly different depending on auto or manual trans but I have an auto exhaust on my manual car with no issues