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Forum namePerformance/Engine
Topic subjectwhy can't we use a straight pipe on our cars
Topic URLhttps://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=16054
16054, why can't we use a straight pipe on our cars
Posted by opie1, Feb-28-02 06:33 AM
ok i want to know the real reason why we cant use a straight pipe on our cars. I know one of the reasons is the \OBDII horseshit. will it throw a code or will if screw up the ecu. I need help PLEASE
16055, RE: why can't we use a straight pipe on our cars
Posted by mcgyvr, Feb-28-02 06:48 AM
you can and here is the trick for removing the cat and not getting a cel http://www2.cesa12.k12.wi.us/brent/personal/neon/
16056, RE: why can't we use a straight pipe on our cars
Posted by SunBlocker, Feb-28-02 06:49 AM
Well, if you are talking about removing your catylitic (sp?) converter and putting in a test pipe, you aren't supposed to do that because of the smog regulations. Federal law states that if you remove a perfectly good catylitic converter that is against the law and punishable by a fine of up to $1400. Although, not many people are fined for this, because its hard to prove that the catylitic converter you removed was in perfectly good working order. Do you have emission testing in your state? If you do, you will not pass your emission test with a "strait pipe". I don't have emission testing in my state so I am one of the lucky ones. Have fun and just don't get caught. :)
16057, RE: why can't we use a straight pipe on our cars
Posted by MrClean125, Feb-28-02 06:54 AM
It has to do with emissions and smog tests and junk. The straight pipe eliminates the catalytic converter which helps reduce the carbon monoxide and shit produced by internal combustion engines. Removing the cat and replacing it with a straight pipe helps the spent exhaust gases escape from the engine faster thus producing more power, but it also lets those dangerous gases through unchecked (i know a very brief, untechnical overview). If you are lucky enough to live somewhere where you dont have to go through a smog inspection (like florida where i live) then it doesnt matter. Well, there you have it.

If i am wrong, by all means, someone please correct me.

Peace
16058, RE: why can't we use a straight pipe on our cars
Posted by Breezio, Feb-28-02 07:42 AM
A guy on another board I check says that if you remove the cat on a good running fuel injected car.. it will still pass a tail-pipe emissions test just fine.. if it doesn't.. put new plugs and wires in and it should pass. all of his cars don't have cats and he's never had a problem with emissions.. one of them is a 89' grandam with 200K miles on it.. no cat, still passes emissions. I'm not saying that any car will.. but according to this guy, it should be fine.. as long as they don't look under you car and be like "hey.. where is your cat?" hehe. in that case you can always put a hollowed out cat with a straight pipe inside of it (so as not to put a big bad air box in your exhaust) and then it'd still look like you had a cat.
16059, RE: why can't we use a straight pipe on our cars
Posted by Dave_FL, Feb-28-02 08:23 AM
i HAVE BEEN "CAT LESS" for about a month or two and still have no check engine light. I have a OBDII car too. Mine is a 97. I dont know where people started the whole CEl if you take off the cat. But whoever did was just trying to scare us I guess.
16060, RE: why can't we use a straight pipe on our cars
Posted by fasterGS, Feb-28-02 10:17 AM
Your car might very well pass the smog test, but in most states where emmision testing is required they do a visual inspection as well, which means they stick their head under the car and look for the cat.
16061, RE: why can't we use a straight pipe on our cars
Posted by Dave_FL, Feb-28-02 10:30 AM
Thats when you make a fake outer box piece out of the old cat. Or just punch a hole through your cat with a pipe.
16062, RE: why can't we use a straight pipe on our cars
Posted by eclipse804, Feb-28-02 11:22 AM
Technically, the whole point of OBD2 and having an aftercat o2 sensor is to tell you if your emissions is bad. It's supposed to detect no cat, but maybe your emissions are so clean it's still like stock.
16063, RE: why can't we use a straight pipe on our cars
Posted by Super20G, Feb-28-02 12:02 PM
I run straight pipes from turbo back.. no problems, no o2 sensors, no cat, no resonators.. no performance problems, i get o2 sensor codes, but who cares... its well worth it.