# header help **URL:** \ **Category:** PittSpeed Automotive\ **Created:** [February 20, 2008, 10:33am UTC](https://forums.speedlife.net/t/header-help/195627 "2008-02-20T10:33:28Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![slowcivic98](https://avatars.discourse-cdn.com/v4/letter/s/4bbf92/32.png) [@slowcivic98](https://forums.speedlife.net/u/slowcivic98)\ **Post date:** [February 20, 2008, 10:33am UTC](https://forums.speedlife.net/t/header-help/195627/1 "2008-02-20T10:33:28Z")
well i put a new header on with a test pipe and ran it wit out o2 sensors for a day i reinstalled the o2 sensors and my check engine light is still on? do i just need to get my comp cleared or is it because i dont have a cat? ---
**Author:** ![dyingwish](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/dyingwish/32/6041_2.png) [@dyingwish](https://forums.speedlife.net/u/dyingwish)\ **Post date:** [February 20, 2008, 10:41am UTC](https://forums.speedlife.net/t/header-help/195627/2 "2008-02-20T10:41:37Z")
Your Civic is OBD2 right? Have the code reset via an OBD2 code reader. I can’t remember if pulling the 15A ECU back-up fuse will clear that in OBD2a/b cars. Why in the hell would you drive a car with no O2 sensors? How in the hell do you think the car knows how it’s intended mixture is burning? I hope it was fun washing your cylinder walls with fuel, drastically reducing the life of your rings. Cheers ---
**Author:** ![ZEX350Z](https://avatars.discourse-cdn.com/v4/letter/z/87869e/32.png) [@ZEX350Z](https://forums.speedlife.net/u/ZEX350Z)\ **Post date:** [February 20, 2008, 10:58am UTC](https://forums.speedlife.net/t/header-help/195627/3 "2008-02-20T10:58:50Z")
> [@slowcivic98"](#): > > do i just need to get my comp cleared or is it because i dont have a cat? ok…this question is retarded. If you don’t have a cat, the secondary 02 sensor is going to read rich. Get yourself an emulator, then… read up before asking such stupid questions and ruining your motor (although the probability of that is pretty small unfortunately.) F’n noobs. You own a honda. There is TONS of info on how to do things right. If you are to lazy to research at all, just stick with the vinyl stickers on your car. ---
**Author:** ![slowcivic98](https://avatars.discourse-cdn.com/v4/letter/s/4bbf92/32.png) [@slowcivic98](https://forums.speedlife.net/u/slowcivic98)\ **Post date:** [February 20, 2008, 11:21am UTC](https://forums.speedlife.net/t/header-help/195627/4 "2008-02-20T11:21:08Z")
ok well im real sry that this is my first car and these are all my first experiences and im real sry all of yins r to big a assholes to actually give real answers to better my knowledge about my car but thx and dying wish ya it is obd2 and i really appreciate u actually giving me a real answer that will actually really help ---
**Author:** ![slowcivic98](https://avatars.discourse-cdn.com/v4/letter/s/4bbf92/32.png) [@slowcivic98](https://forums.speedlife.net/u/slowcivic98)\ **Post date:** [February 20, 2008, 11:24am UTC](https://forums.speedlife.net/t/header-help/195627/5 "2008-02-20T11:24:37Z")
and i only had to get it home from the garage i was at that was maybe 5 blocks so it wasnt for very long and i kno its not good to run ur car wit out o2 sensors but i had no choice period ---
**Author:** ![dyingwish](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/dyingwish/32/6041_2.png) [@dyingwish](https://forums.speedlife.net/u/dyingwish)\ **Post date:** [February 20, 2008, 11:26am UTC](https://forums.speedlife.net/t/header-help/195627/6 "2008-02-20T11:26:04Z")
Unfortunately you’ll have to go to the nearest Autozone/PepBoys/whatever and have them clear the code. If the code-throwing event is still present it will either throw it again immediately…or it will throw after 50 miles. Sometimes exhaust leaks around the cat will throw them. ---
**Author:** ![slowcivic98](https://avatars.discourse-cdn.com/v4/letter/s/4bbf92/32.png) [@slowcivic98](https://forums.speedlife.net/u/slowcivic98)\ **Post date:** [February 20, 2008, 11:27am UTC](https://forums.speedlife.net/t/header-help/195627/7 "2008-02-20T11:27:49Z")
my uncle was gonna clear the code for me but its still going to throw a catalyst code aint it? because im running a test pipe i mean i am buying a hi flow cat but now that i have the o2 sensors in am i still hurting anything? ---
**Author:** ![dyingwish](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/dyingwish/32/6041_2.png) [@dyingwish](https://forums.speedlife.net/u/dyingwish)\ **Post date:** [February 20, 2008, 11:33am UTC](https://forums.speedlife.net/t/header-help/195627/8 "2008-02-20T11:33:46Z")
Yes and no. Without a cat to scrub your exhaust gasses, and give the O2 sensor a clearer picture of what is happeneing in the cumbustion chamber, then the computer will compensate by running SUPER rich. Basically the sensor is seeing way too much oxygen, which the ECU interprets as NOT ENOUGH FUEL…and dumps lots more _uneeded_ gas into the cylinder. This in turn washes the cylider walls, wears out rings, etc, etc. There is ZERO gain to running a high-flow _test-pipe_ on the street. Any good 200/300/400 cell catalytic converter will flow almost identically to a straight pipe. All you are doing is harming your motor, possible even exhaust velocity. I would lose the test pipe and either buy a new higher-capacity cat, or put the stock back on. I guarrantee your aren’t built nearly enough to be bottlenecking your current cat. ---
**Author:** ![slowcivic98](https://avatars.discourse-cdn.com/v4/letter/s/4bbf92/32.png) [@slowcivic98](https://forums.speedlife.net/u/slowcivic98)\ **Post date:** [February 20, 2008, 11:37am UTC](https://forums.speedlife.net/t/header-help/195627/9 "2008-02-20T11:37:18Z")
to be honest the catback and header r my first so called real mods will my stock cat fit back on my exhaust the stock cat has an inlet and outlet of 1 7/8 and the new exhaust is 2 1/4 i was jus goin to buy one of the obd2 50 state legal hi flow cats off summit ---
**Author:** ![dyingwish](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/dyingwish/32/6041_2.png) [@dyingwish](https://forums.speedlife.net/u/dyingwish)\ **Post date:** [February 20, 2008, 11:43am UTC](https://forums.speedlife.net/t/header-help/195627/10 "2008-02-20T11:43:50Z")
Consider this your first learning session. It’ll fit, provided the two-bolt flange that connects lies at the same angle/position as the header does. Ideally you should have the same inner diameter from the collector to the muffler, to keep the exhaust energy constant, and flowing freely. You _can_ however, have an exhaust that steps up slightly going from front to back…this creates small pockets called anti-reversion chambers…which are good. You never want to get smaller as you go back. If you need a cat for the exact setup you have just bought, but a universal magnaflow or something…call Jeff @ 1st Try…and voila, a matched setup that’ll work just fine. ---
**Author:** ![slowcivic98](https://avatars.discourse-cdn.com/v4/letter/s/4bbf92/32.png) [@slowcivic98](https://forums.speedlife.net/u/slowcivic98)\ **Post date:** [February 20, 2008, 11:46am UTC](https://forums.speedlife.net/t/header-help/195627/11 "2008-02-20T11:46:48Z")
thats exactly wat i was gonna buy a universal magneflow off of summit. so that’ll work then and i should pass emissions then rite? well any ways i really do appreciate ur help and u not being a smartass like i sed this is my first car and im not real sure of anything. but wen ppl r assholes im not learning nothing but thx alot man ---
**Author:** ![tegSimple](https://avatars.discourse-cdn.com/v4/letter/t/d6d6ee/32.png) [@tegSimple](https://forums.speedlife.net/u/tegSimple)\ **Post date:** [February 20, 2008, 11:53am UTC](https://forums.speedlife.net/t/header-help/195627/12 "2008-02-20T11:53:52Z")
> [@slowcivic98"](#): > > ok well im real sry that this is my first car and these are all my first experiences and im real sry all of yins r to big a assholes to actually give real answers to better my knowledge about my car but thx welcome to pittspeed, people are assholes most of the time. > [@FS: Green 17" Racing Hart wheels](https://forums.speedlife.net/t/fs-green-17-racing-hart-wheels/29209/29): > > to be honest the catback and header r my first so called real mods will my stock cat fit back on my exhaust the stock cat has an inlet and outlet of 1 7/8 and the new exhaust is 2 1/4 i was jus goin to buy one of the obd2 50 state legal hi flow cats off summit good choice. as a recommendation, get a cat with floating flanges as it makes it much easier to bolt up. this recommendation comes from dyingwish. if you haven’t already done so, make sure to get 2.25" donut gaskets for it as well. ---
**Author:** ![yamaha](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/yamaha/32/5929_2.png) [@yamaha](https://forums.speedlife.net/u/yamaha)\ **Post date:** [February 20, 2008, 1:30pm UTC](https://forums.speedlife.net/t/header-help/195627/13 "2008-02-20T13:30:35Z")
He finally put the oxygen sensors back in his car. He rushed into this and hopefully learned his lesson. Adding a catalytic converter and glasspack will hopefully quiet the damn thing down. It sounds like pure shit. ---
**Author:** ![slowcivic98](https://avatars.discourse-cdn.com/v4/letter/s/4bbf92/32.png) [@slowcivic98](https://forums.speedlife.net/u/slowcivic98)\ **Post date:** [February 20, 2008, 8:02pm UTC](https://forums.speedlife.net/t/header-help/195627/14 "2008-02-20T20:02:08Z")
hey yamaha just think u helped contribute to the rice burner :bj: