325i exhaust system

[satvir]

My catalytic converter and back box are rotten and blowing. Ideally i would get new stainless steel system etc, but im looking for a salvaged second hand one just for my MOT.

Just wanted to know can any back box fit on to my system. Or do i need a particular back box as my system has a catalytic converter?

Cheers

[HairyScreech]

there are 2 and 3 piece systems, the three piece has longer pipes extending back from the center box to the back box than the 2 piece.
You need to have a look where your back box pipes join the center box before you do too much looking.

However if you get a full downpipe back system with the downpipes to match then you should be able to fit that to any 6 pot e30.

[satvir]

From what i can see it,s 2 piece. From the manifold, the downpipe and cat are one piece (being the largest section) from that joins on the backbox.

[Grrrmachine]

I had a cat on my 320i, and the back box was blowing when I got it. Standard 6-pot facelift backbox was fitted and is still working 3 years later.

[satvir]

How much would it affect the MOT if i was to replace my two-peice system with a mid box silencer rather than the cat that is already in place? Finding a used cat it hard to come by and new one costs about £240.

[HairyScreech]

You in the uk?If so as long as the car is pre 1992 then its absolutely fine, there is also a loop hole for cars/engines up to April 1995.

[satvir]

yep UK and the car is '89 plate! So i can replace the entire system (manifold back) and without cat and it shouldn't be an issue with emmisions of whatever? Can u tell me more about this "loop whole for engines"

[Rtaylor2208]

Are you sure it has a cat being an 89 car. The two piece system has front and rear silencers but no cat from what I have been told. I know my 89 cabby with 2 piece system (front section OEM, rear aftermarket) certainly doesn't.

[satvir]

So my 325i '89 convertible shouldn't have a cat ?

It looks like a cat, flat and thin compared to what normal middle section boxes look like. I want to upload a pic but don't how to over this!

As long as i can get away without having what appears to be a cat and still be okay for emissions is the main thing.

[satvir]

Print out i got from BMW showing me what my car came with as standard does state :

"200 * Delete Catalysor"

That mean it came without a cat?!