jmckella

I'm decatting my car before it's remap, how much bhp would I gain by removing the cat ?

cheers Jase.

martwrxsl

Maybe 20-30bhp because they can turn the boost up more with no cat in the up pipe.

jmckella

Nice one, I'll definitely change this then.

jmckella

I've just phoned scoobyworld to order my exhaust and was told I don't need an uppipe as there isn't a cat on the 05wrx.
Can someone please clarify this.

Henrik

iTrader: (5)

I'm pretty sure there's one on all the bug and blob wrx's, isn't there? The STI's on the other hand don't have up-pipe cats.

The easiest way to make sure is to look at it, if it has a bulge where the sensor attaches, then it's got an up-pipe cat (in fact, if it's got a sensor, it must have a cat, as it's a "cat on fire" sensor)

Wurzel

iTrader: (1)

I think you re confusing the up pipe and the downpipe! the down pipe is the one with the cat and sensor in it, and comes out of the turbo and dissapears under the car , you can't see the uppipe as it is routed from teh exhaust manifold up through the side fo the engine and into the bottom of the turbo.

Speech

There's an EGT (Exhaust Gas Temperature) sensor in the WRX up-pipe as well mate.

Jase, when you remove the sensor there is a quick mod involving a resistor to fool the ECU into thinking all is well, but they can get upset at seeing a constant value for the temp and throw a CEL light, but this is easily removed by your mapper.

wrxseeker

iTrader: (1)

MY MY05 WRX had an uppipe Cat, a down pipe cat & a centre cat .... which are now all in the loft at home

Henrik

iTrader: (5)

Umm, no. I can see mine perfectly fine viewing from above (granted, there's a bit of cables and stuff in the way, but apart from that it's clearly visible.

Graz

Newage WRX has up pipe cat, STI does not.

Definitely get rid, not only will it flow the exhaust gases better but there is also a risk of the up-pipe cat breaking up when the boost is increased. Where do the bits of metal go when it breaks up.......

...... into the turbo, new turbo time ££

jmckella

Cheers guys. It sounds like there's probably an uppipe cat so I'll remove it to be on the safe side, if not does anyone want to buy an uppipe !!Lol.

mbayley77

iTrader: (4)

Does a Spec C have an up pipe CAT then? (2003)

jmckella

Will it pass the MOT with no uppipe cat, no centre cat and a 100cell sports cat ?

Henrik

iTrader: (5)

Yep, will be fine. I've got this setup and it passed emissions with flying colours (Prodrive PPP downpipe)

jmckella

cheers Henrik.

wrxseeker

iTrader: (1)

Mine passed too

codie247

And mine.

Lee