Has anyone with an OBDII (2 o2 sensors) got a test pipe on their car that works properly. I heard running with a straight pipe 1) makes your exhaust louder 2) Will mess up your 02 sensor 3) increase HP alot esp. with a turbo. I'm thinking "hey I really don't need to be smog legal on the road when I'm going to get smogged at a 'special' smog shop. THAnks

ALvin

I don't have any problem with my gutted cat. I have a 96 also.

He he this is an old trick from around the block. The way we "use" to do it would be to get a stock cat cut the cat cover off of it and then make a straight pipe w/ flanges and weld the cat cover on it to resemble a cat, it works and the flow was great. Your going to have to find a shady shop to do it but its well worth it. The fact is without a cat the turbo flows better and it doesnt really need the backpressure. The other alternative is to get a high flow cat. Welp just my opinion, plus if you ever ran super rich youve probably got a shitload of carbon build up and I'm almost positive everyone has ran rich. people might say that without back pressure you are going to have a bigger lag on spoolup. But the other side to this is that with quick spool up you bake the tires off. So go with the better flow and you will be rolling at 10 to 15mph when the boost kicks you in the tailpipe. late mike

So what would happen if the two o2 sensors read the same reading?..I just don't want any loss of MPG or any CELs.

ALvin

the sensors are on the header and on the pipe after the cat. Man lets put it this way about the blinky blinky light once you go turbo remove the bulb. It will burn out eventually. And if anything its gonna get batter gas milage unless you like reving the shit out of it cause of the new cool sound. late mike

You will get a CEL. If anyone knows what voltage the sensor needs to read in order not to get a CEL, please post it. If we can figure that out, then you can use a voltage clamp to prevent that. Personally, I would never rempove the CEL or run with it on all of the time unless you have a datalogger and you use it often. Otherwise, you will never have a clue if there is a real problem under the hood.

YOU WILL NOT get a CEL. I am proof of it. I have a OBDII 1997 eclipse GS and I have had my straight pipe on for about 2 months now and still no CEL. Just about everyone I have talked to that has a Straight pipe or a gutted cat never got a CEL. I dont know where this myth came from but it isnt true.

Does having a straight pipe or a gutted cat make the exhaust that much louder? How loud is it compared to a basic cat-back exhaust, for instance, a Greddy EVO or Apex N-1? I'm thinking about gutting my cat-converter until I can afford a real hi-flow cat.

Its a little bit louder but not to bad. I dont think any exhaust can be too loud on our cars. We are not V8's. maybe if you just had a down pipe it might be too loud.