[IllestBeams94]

So i'm trying to do some research on removing the cats fom my car, but i read that there are 4. Is it true? I only want to remove the secondary in that case. Thanks forum

[Volasko]

We have two cats, one on the header (very hard to remove) and one midway on the exhaust.

[SDemetris]

Originally Posted by Volasko

We have two cats, one on the header (very hard to remove) and one midway on the exhaust.

not totally true. Our headers are split between cylinders 1-3 and then 4-6. Each goes into a collector where there is a cat. So there are 2 large cats in the headers. Then further under the car there is another set of 2 smaller cats. So 4 total. I got my secondaries removed with no problem for just a little more than I recieved for taking the old cats to a junk yard to sell. I highly recommend removing those two

[Kalidian]

Originally Posted by SDemetris

not totally true. Our headers are split between cylinders 1-3 and then 4-6. Each goes into a collector where there is a cat. So there are 2 large cats in the headers. Then further under the car there is another set of 2 smaller cats. So 4 total. I got my secondaries removed with no problem for just a little more than I recieved for taking the old cats to a junk yard to sell. I highly recommend removing those two

What benefit is there to removing the secondary cats on the midpipe? Does it just make it louder? I'm looking to get a PE and when I get that I may look to get those deleted at the same time.

[SDemetris]

Originally Posted by Kalidian

What benefit is there to removing the secondary cats on the midpipe? Does it just make it louder? I'm looking to get a PE and when I get that I may look to get those deleted at the same time.

it makes it a bit louder, but not too much.. I saw a before and after dyno of a car with the magnaflow catback (similar to BMW PE) and they gained 9rwhp from taking them off. So a little bit of power too.. Its easy to take those ones out though because there is no O2 sensor after them so you dont get any codes like you do with the main headers.

[IllestBeams94]

Thanks so much, this was a LOT of help, once i get the car back from the shop for my clutch, ill work on the exhaust and ill post a video here

[Rival]

Originally Posted by SDemetris

it makes it a bit louder, but not too much.. I saw a before and after dyno of a car with the magnaflow catback (similar to BMW PE) and they gained 9rwhp from taking them off. So a little bit of power too.. Its easy to take those ones out though because there is no O2 sensor after them so you dont get any codes like you do with the main headers.

9rwhp from 2nd cat delete?? sounds lofty....


im going to do them but didnt think there was that much to gain....i figured like 2-3rwhp...

hope your right.

[SDemetris]

http://www.e90post.com/forums/showthread.php?t=703329

[Rival]

Originally Posted by SDemetris

http://www.e90post.com/forums/showthread.php?t=703329

thanks.

[Hybrid For Life]

how are you guys going about doing the secondary cat delet? Hva eht emuffler shop make you a test pipe or do you just weld in a section of tubing?

[SDemetris]

Originally Posted by Hybrid For Life

how are you guys going about doing the secondary cat delet? Hva eht emuffler shop make you a test pipe or do you just weld in a section of tubing?

I took it to a shop and told them to take them out and put in SS pipe