KAT-engine on non-kat exhaust?

[AndersLS]

Hello guys....I know I have asked a similar question to this.....but, my mechanic says that he has never heard of a "valve" you can block off on the engine and then mount the exhauts. He says I would need a lambda
-thingy...even though I don´t have a cat.. What gives? Kat-engine and non kat exhaust with non-kat ecu....would this be enough? Dr. ant?
I hope you undertand..............

[reggid]

Firstly we need to establish the differences between the Engine fitted with a Kat and one without a Kat. I believe the Kat engines have a CR of 8.8 and non cat 9.7. As for the other differences i don't know/ can't remembert

I don't see any reason why you couldn't remove the Kat (which is the equivalent to what you are asking) except possible emission laws which i know we have here in OZ and its a $5000 fine

[Brianmoooore]

Hello guys....I know I have asked a similar question to this.....but, my mechanic says that he has never heard of a "valve" you can block off on the engine and then mount the exhauts. :

Valve in quesrion is probably an EGR (exhaust gas recirculation) valve; a horrible arrangement used by some lesser manufactuers which feeds exhaust gasses back through the engine.
It's a common mod on LPG power cars to blank this off.
No BMW that I know of was ever fitted with this.
All facelift BMW engines are "cat ready" so the short answer is that there are no differences, other than, I think, the chip in the ECU is different

[AndersLS]

Hello Brian.....ok....I put the cat-engine in...mount the non-cat exhausts
and put in a non-cat ecu? Is this correctly understood? Please confirm that the engine won´t run unstabley.!

My mechanic says...if I don´t put in the lambda-thingy...it will use to much fuel...is this correct?

any info highly appreciated.

[Brianmoooore]

Non cat version of the ECU, and the engine won't miss the lamda sensor

[lefty325i]

My car had a cat but i had to use the hego sensor as it wouldnt run!