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I'm finally upgrading my cat. Can anyone recommend a good hi flow?

Any, most cat's are the same.

Stromung makes a good bolt up highflow cat
Although the fitament might be a little different on turbos...it'd probably just be best to get a universal high flow (like magnaflow) for pretty cheap and have an exhaust shop mandrel bend up some pipes for you.

I'd recommend getting a metallic substrate cat instead of a brick one. It'll be more expensive, but it will also make more power, last longer and be smaller. Random makes the one I put on my 00, and may make a WRX downpipe with cat. The easiest way to tell the difference between the two is the size and shape. Metal cats are very short and rounded, like this Cobb unit:

http://cobbtuning.com/wrx/images/downpipe-med.jpg

you dont need a cat...... who wants those?

its actually better if you do have a cat. People tend to fry o2 sensors and have other problems if they get a track pipe, also emissions would be a problem without a cat.

Be nice to the environment.......you do like to breath don't you.

Thanks guys

Carsound-Magnaflow.

I run catless 11 months of the year and haven't had any 02 sensor woes.

I did have o2 sensor woes in the past though when I was catted.

i have a question on this. im gonna have to do emissions this year, in like about, 8 months, and i was looking towards a hi-flow cat. right now i just have a 3-inch SS bellmouth downpipe. would all i need to pass emissions be the 1 hi-flow cat?

Are you guys able to pass emissions that way? i just dont want to have to retake an emissions test cuz it didnt work... thanks in advance.

anything at all guys? hi-flow cat guaranteed to pass emissions no matter what right??

wiscon_mark wrote:its actually better if you do have a cat. People tend to fry o2 sensors and have other problems if they get a track pipe, also emissions would be a problem without a cat.

Another point Mark, the O2 snesor is pre-cat on the turbo BC/BF.

Project_Legacy wrote:i have a question on this. im gonna have to do emissions this year, in like about, 8 months, and i was looking towards a hi-flow cat. right now i just have a 3-inch SS bellmouth downpipe. would all i need to pass emissions be the 1 hi-flow cat?

Are you guys able to pass emissions that way? i just dont want to have to retake an emissions test cuz it didnt work... thanks in advance.

It depends on the area. I don't know what Washingtons emission laws are but here in PA, I pass with just the one mid-pipe high flow cat.

legacy92ej22t wrote:Another point Mark, the O2 snesor is pre-cat on the turbo BC/BF.

uh, I have one as well, but I have 2 o2 sensors, one pre-cat, one post-cat. Is this an OBDII feature only?

thanks for the info. i was askin becuz i know i am running a lil rich even at idle because i am using an all stock ej22t fuel system on my ej20g/ej22t frankenstein motor. im worried about not passing emissions. does anyone here in the washington state area know anything about this???

The second O2 sensor for OBD2 is a tattle-tale sensor. If the wave mirrors the front sensor, it throws a CEL saying the cat is inefficient.

That's its only job. To tell the ECU that you don't have a cat.

oh, okay, thought so.

Having a cat wont garantee that you pass emissions. You engine still has to run clean.

If you are running rich, and fail because you are running rich, I bet you could install a 50k poteniometer into the MAF signal line and pull fuel just for the test. ie, you trim the MAF signal about 10%, which trims fuel.

uhh. does that work like an AFC? sounds similar. how would i be able to figure out how much fuel i would need to trim? does anyone have injector numbers for the ej20g? i heard of 2 of em. 440cc and some other number. the ej22t has 370cc injectors right? is it safe to say that the ej20g's with the vf8/vf12's had the 440cc's and the ej20g's with the vf10 had the lower numbered ones? i always wondered about that. can anyone confirm this??

I passed Oregon DEQ last year. No cat, 234,xxx miles.

Anyone know anything about cats that are designed to withstand anti-lag?

Ive seen a few on the net but I dunno if they're actually any better

rallitektech wrote:I passed Oregon DEQ last year. No cat, 234,xxx miles.

is that car stock? i know my car is running rich so i doubt i will pass.


anyone have an answer for my injector question??