if i was to remove my cat....

[Bengali86]

heya


I made a post a bit ago bitchin about my car, the tires and catalytic ect..


I have made the decision to remove my catalytic completely, since i dont have to do emissions for 1 year 5 months, that will give me time to save some dough.

If i remove the cat, and replace it with straight pipes from the headers to the muffler, would there be a large increase in noise? would there be a performance increase/decrease?

thanks for any info!

[dutchbmw]

There is an increase of noise, more like a lower/heavier noise....... Racier I guess!

Theoretical there is also an increase of power, but when there are two O2 sensors (before and after cat., it's the OBDII system) it could be the engine management (Bosch Motronic) should switch over to the emergency course. This means a more bad mileage and even a DECREASE of power.

[Bengali86]

Originally posted by dutchbmw@May 23 2004, 03:15 PM
There is an increase of noise, more like a lower/heavier noise....... Racier I guess!

Theoretical there is also an increase of power, but when there are two O2 sensors (before and after cat., it's the OBDII system) it could be the engine management (Bosch Motronic) should switch over to the emergency course. This means a more bad mileage and even a DECREASE of power.

Thanks for the info!

its a 93, so OBDI

one (?) O2 sensor infront of the cat.

[El Presidente]

correct. The precat o2 sensor would still have to be mounted somewhere though.

[Bengali86]

Originally posted by El Presidente@May 24 2004, 01:41 AM
correct. The precat o2 sensor would still have to be mounted somewhere though.

is it possiable just to drill a hole and place the O2 sensor there? or is there somthing special i would have to do..

during lunch today, im going down to the local muffler shop and see what they can do for me, hopfully ithis will be easy and inexpencive, As emissions time rolls closer, i will invest in a bolt on, so i could swap out the cat for straigt pipes, and back again, I will let you guys know what happens at the mufler shop today

Thanks
Ben

[IvanB]

i had the stock cat changed to an aftermarket cat and it got alot noiser. I can imagine w/o a cat at all its going to be even louder -- thats with stock muffler.