It's simple cat delete more power, but cel. High flow less power, but no cel. I went high flow but now I will be buying a cat delete soon.

 

Yeah, but for those of us who can get slapped with a nice illegal fine for going catless, it's probably safer to get a highflow cat.

 

I have both a 3" high-flow cat and a 3" test-pipe for my Eclipse. Just changing to the test pipe, DSMLink shows a 1.5lb/min increase (about 15HP) up top. The test pipe is definitely the way to go for more power, better spool-up, etc.

The only downsides are the noise, a noticeable exhaust smell, and obviously the fine if caught. I get tired of the test pipe once in a while and put the hi-flow cat back in. Much quieter and no smell. But, if you are going to run leaded gas, you cannot use a cat or it will be ruined.

Eric

 

It depends on where you live. If you're in Cali, you run the risk of getting a $2k fine for running w/o a cat. Now is this risk worth 10hp? I'd rather go w/ a high flow cat. It won't give you as much hp, but at least you'll be legal. There are plenty of other ways to get another 10hp.

 

thats what im running.. no CEL since day 1... been on about 2 months... exhaust has a nice bass to it at idle but my wifes WRX's boxer 4 drowns that out when she starts hers up..... i say catless ...and here in Oklahoma no emissions... im lovin it.

 

Going from a UR high flow cat to a UR test pipe, it's really not THAT much louder, but it does drone a little bit on the highway. I noticed 200 rpm better spool-up (21 psi at 2750 rpm in 4th gear) and it helped pick up a few hp across the powerband.

 

Removing the catalytic converter on a street driven vehicle is illegal in ALL states (it's a federal issue). Whether you stand a reasonable chance of getting caught or not is what one has to consider.

 

going catless is louder if you use an aftermarket exhaust. with the stock catback it sounds the same.

 

Just an FYI.. the smell is very obvious when you are driving behind a car that's catless. I am sure cops will know what's going on if they're behind you.

 

I have a 3" catless turboback and a guy the other night with a Buschur "loud" or whatever exhaust was louder than me! I have no muffler either, just a resonator! Also, the dyno showed about a 30 ft lb gain in torque with no cat (but not as much HP). However, I think I am going to go a different route. I will put the cat back in but get an exhaust cutout for those track days. I'll splice it into the downpipe.

 

Ya I think I might keep the stock cat on with my BR turboback. I bought the test pipe but now you all have me scared I'll get caught. Anyone know what the fine is in Maryland?

 

It's like 2K in TX I think. Its no joke to get caught.

 

Damn that's 2K in two states now- maybe the fine is a federal law too. Screw that. Stupid environment


<------------Hey look- I > 100 posts.

 

i think i know why

 

It would be easy to go to court and say that a nearby gas powered lawn mower or generator was the source of the odor. Even if the cop visually observed a de-cat pipe he wouldn't be able to prove that it was not a catalytic converter without removing it and presenting it to the court. All you would have to do is argue that the cop made a mistake and mis-identified the cat converter. His entire arguement would be based on assumptions. Case dismissed.