I am new to modifing cars. I was just wondering how do you pass the emissions test with modified exhaust, intake etc. Wouldn't these parts make you fail the test? I just wanted to know how do you pass the test with modified parts. Thanks

depends on what kind of car you have , and what year.. alot of aftermarket parts are emissions-friendly or whatever they call it now. california is tough on smog... but anything older than 25 years is exempt, so im safe hehe.

i hear lotsa stories of guys retarding their ignition timing , and running the car alittle lean for smog tests, then changing it back afterwards... i dont know how well it works, cause ive never had to smog a car.

i have a 2000 honda civic si

An exhaust won't make a difference as long as it's cat-back. An intake must be CARB exempt, i.e. have a CARB # sticker on it for it to pass legally. Same goes with a header.

-Ben

lol Id just keep your stock stuff when u take it off, thats what i did, i have my stock headers, dp, and intake sittin in my garage. I think its worth the space when smog time comes.