[A29er]

Hello everyone, I am new in the forum and to the SUBi world, I acquired a 03 wrx, but the up pipe catalytic is damaged, so is the turbo, does anyone know if replacing the up pipe without a catalytic will affect the emissions in California.?

 

[silver_scooby]

Yes it will fail inspection, both visual & emissions codes. You are also SOL for tuning catless unless you spend 6k+ on a standalone ecu or find an extremely friendly tuner who is willing to risk massive fines and is capable of open source or ecutek tuning.

If you try to run catless without tuning, best case the car will go in limp mode for emissions codes, worst case engine explodes.

 

[A29er]

Thanks Silver

 

[silver_scooby]

Sure, and welcome to the club. Post some pictures of your car, blobeyes look brilliant.

 

[XJman]

Yes it will fail inspection, both visual & emissions codes. You are also SOL for tuning catless unless you spend 6k+ on a standalone ecu or find an extremely friendly tuner who is willing to risk massive fines and is capable of open source or ecutek tuning.

If you try to run catless without tuning, best case the car will go in limp mode for emissions codes, worst case engine explodes.

I don't think the up pipe cat needs a tune at all.

It may or may not fail. It's a hugely common modification to remove it because of the issue you are having right now.

 

[silver_scooby]

I don't think the up pipe cat needs a tune at all.

It may or may not fail. It's a hugely common modification to remove it because of the issue you are having right now.

That's interesting, how do you avoid emissions codes and boost creep if there's no catalyst on exhaust?

 

[XJman]

That's interesting, how do you avoid emissions codes and boost creep if there's no catalyst on exhaust?

This cat doesn't exist in other models. It was only on the bugeye if I remember. The only member I know that would deal with a stock bugeye but may have removed the uppie cat would be @SD_GR.

 

[goldenmonkey]

Everything I've read says going catless on the uppipe does not require a tune.

 

[silver_scooby]

This cat doesn't exist in other models. It was only on the bugeye if I remember. The only member I know that would deal with a stock bugeye but may have removed the uppie cat would be @SD_GR.

Ah ok, I figured it was the only catalyst on the car.

Everything I've read says going catless on the uppipe does not require a tune.

My mistake, I assumed it was the only cat. Maybe the member xj mentioned will comment.

 

[XJman]

Ah ok, I figured it was the only catalyst on the car.


My mistake, I assumed it was the only cat. Maybe the member xj mentioned will comment.

Yeah it was a bizarre design choice. They are a catastrophy waiting to happen.

I've heard you can get away with deleting it and nobody is any wiser, however I don't live in a state that checks anymore and I can't speak to it.

 

[silver_scooby]

I guess gutting the stock cat is one way to pass visual inspection if it doesn't affect stock tune or throw codes.

 

[SD_GR]

My car is in California and is an 02 model with the stock up pipe cat.

The cat failed and I removed the stock up pipe, and replaced it... with a stock up pipe (thanks Sasquatch!).

I may be the only person on this forum who has replaced a catted up pipe with another catted up pipe.

There are other options but I wanted my car to be completely stock.

One option is to replace the up pipe with a stock up pipe from a later car, that is catless. This could help with the visual inspection because the stock up pipe doesn't look suspicious at all. You'll then have a CEL to deal with, but you can do that with a resistor. Disguise your wiring and you could be OK - no promises bc people like me can tell if we look (but I don't know if the inspector will have owned a WRX for 20 years like me...).

Another option is to go with an aftermarket up pipe. Pick the ugliest one you can find, not the shiniest, fix the CEL with a resistor as above, and hope he doesn't know where to look.

 

[mjtct]

Later years no CAT in up pipe. I bought one from IAG for $40. Come to find out mine was already gutted so I have a spare if you want to pay for shipping. There is a temperature sensor in that pipe. Mine was just sitting loose in the engine bay and I had no codes unless that was deleted somehow.

 

[bctr]

This is my first post in this community. I'm the original owner of a 2002 WRX. It is all stock except for upgrading the leaky radiator and installing a catless uppipe. There are 3 CATs on the 02-05 WRX, one is before the turbo. This one should be replaced; as CATs age they can flake off material that will trash your turbo. I was prepared to use a resistor, if necessary, and/or tune the car. Neither was needed, there are no CELs and it runs great. I have been in for emissions tests (not CA), passed easily, and the emissions were almost identical to the results with the uppipe CAT. There are still 2 more CATs on the system. The car runs great, just like it has for over 20 years.

 

[bctr]

For more detail on the CATs Catalytic Converters (CATs), Emissions Testing, Emissions CELS, and you. | Subaru WRX Forum (wrxtuners.com)

 

[drew935]

Hello everyone, I am new in the forum and to the SUBi world, I acquired a 03 wrx, but the up pipe catalytic is damaged, so is the turbo, does anyone know if replacing the up pipe without a catalytic will affect the emissions in California.?

You will need some tuning. Although, 02-03 are more open to accepting mods without tuning to a degree.
04 + subies aren't as open to mods without tuning.

 

[WTypeRogerX]

Bugeye and blobeye WRXs come with catted uppipes, but they are not needed as the STi versions didn't come with them. On my 2005 WRX, I replaced the catted uppipe with an STi cat-free uppipe as well as the rest of the exhaust with a TXS downpipe and high-flow catted mid-pipe. We have CA emissions dyno tests and it passed them for 12 years before the TXS cat failed. I had the TXS cat cut out and welded in another aftermarket cat that passed emissions.