Cat options

[sdremsw]

My 87 325is has a rusted out muffler (which I'll be replacing), a crack in the piping right below the manifold connection and won't pass smog (California). The crack has been patched but I can't tell if that's the reason it won't pass, if it's the cat or just the muffler.

Anyone have suggestions on the best and most cost effective way to repair and get through smog?

I could go and replace the whole system from the manifold including a Cal approved CAT but this will cost about $550 with a magnaflow system (https://www.autohance.com/magnaflow-...BoC5TQQAvD_BwE).

Including the cost of the new muffler at around $170 this ends up being quite an expensive exercise.

Any help appreciated!

[Siebenthal]

In my limited experience with smog (through my friends who are mechanics and the cars ive brought to my local smog station)

I have smogged an e34 525i with a massive hole in the muffler and a brand new cat (passed with flying colours - even the smog guy was impressed)

Used a rubber mallet to hit the cat on a 325e to check for any movement and there was nothing - also massive hole in muffler (passed)

My 325i vert - hole in muffler - passed

Im pretty sure (my mechanic friends say this too) the muffler has nothing to do with carbon/emissions coming out of your vehicle.

If the crack has been patched, hit the muffler with a rubber mallet and see if anything moves around - if it does - find a cat used (shake it around) or new and you should be fine.

In my area, they offer free retests within 60 days - so if youre worried you can try to find a shop that does the same.

[richardodn]

Did you fail based on physical inspection? What were the numbers from the test?