[Tom s]

Just purchased a 2000 e46 323i and it runs well although the eml and asc light intermittently come on. Doesn’t seem to affect performance at all and goes away if I restart the car.
along with that, the idle is very rough, moves from 1k to 1.4k constantly. Starts mildy when first started but gets worsw the longer I drive. Any help or suggestions would be greatly appreciated

 

[Hot_tub]

do this and make sure you don't have any vacuum leaks for starters. Very cheap test

 

[NZ00Z3]

Welcome to the forum.

Yes doing a smoke test is a good way of finding vacuum leaks. Vacuum leaks are the most commonly occurring problem on E46's. You can find a thread about smoke testing (and a lot of other really useful stuff) in the IMPORTANT LINKS page.