catless up-pipe

[MikeV]

Since I take part in some autoslalom and track, it was suggested to me that I should replace my stock up-pipe with a catless one.

Are there any con's to doing this?

Are the 2007 STi up-pipes catless?

Is there anything that I should be looking for when getting another one?

[JoeT]

What year is your WRX again?

If it's a 2002 / 03, there's an EGT probe on the stock up pipe, you'll need to bridge that with a resistor to prevent CEL's or use an OpenECU or Accessport to turn of the CEL permanently. Nocturn aka Pete can help you with that.

Noticable stuff:
Improved spool, meaning faster boost delivery
Less risk to the turbo (safer) due to reduced risk of the cat substrate from entering the turbo.

Some minuses:
Not much
Increased raw fuel smell during startup (not that much)

After the car warms up, it feels, smells, drives perfectly normal. Just that it'll have better midrange and slightly more top end.

Yes all STI up pipes are all catless.

Hope this helps.

[MikeV]

2005 WRX. I have already have an accessport, so that should take care of the EGT. The car should still pass drive clean right?

Does this one look good to you? up-pipe

Thanks

[JoeT]

All WRX's even with 2 out of 3 cats removed will pass Drive Clean, provided that your spark plugs are in good shape.

[JoeT]

MikeV wrote:
2005 WRX. I have already have an accessport, so that should take care of the EGT. The car should still pass drive clean right?

Does this one look good to you? up-pipe

Thanks

That up pipe looks like it has a cat, unless it's just a wide heat shield. PM the guy that's selling it and ask him if it's a catless up pipe.

[Geoff_Rex]

I had an e-test done on my '02 in May with catless up pipe and down pipe. Passed with flying colours. I can't remember the exact numbers, but it was around 5ppm out of an allowable 150, or something like that.

[Sir-knight]

read somewhere that wrx uppipes turned catless after a certain year because of the cat flying apart into the turbo... might want to look into that possibility on nasioc.

[STeveD]

Hey Mike. Guess what... My coated stock exhaust header and coated stock up-pipe with EGT bung are about to come available...

[vknot]

I am thinking of getting one next year. We'll see....

[MikeV]

I have my car booked in to get Steve's old STi uppipe and Stromung shorty downpipe installed.

Should I reinstall the EGT sensor in the uppipe or plug the bung? Also are the COBB AP CEL defeats all that's required, or do I also need to do the mechanical fix for drive clean?

[JoeT]

Cobb can turn off the CEL for the EGT probe in the up pipe, or you can either leave it in or remove it. But I don't think the STI's had the EGT probe in the up pipe (I can't remember).

You're keeping the stock 2nd cat if you're using the shorty downpipe. It'll pass emissions with that cat, but the CEL will be on.

In Ontario CEL's don't matter as most shops don't care unless it doesn't pass emissions.

[STeveD]

The up pipe had the DeFi EGT bung installed.

I'm guessing that COBB can also turn off the rear O2 efficiency CEL as well because ECUTEK can, and COBB sells catless TBE's and OTS tunes for it. But you should ask someone more familiar with COBB.