Installed new header, questions...

[TheHybrid]

I got my 4-2-1 long header installed today.... first off I had to remove the auxillary AC fan to get it to fit... secondly, the sound.. ugh... It buzzes pretty good... So i'm looking to get rid of that. Would the best (and cheapest) route to mellow it out just be to go to any muffler place and ask them to install a resonator? If yes, any type inspecific (i'll order it)?

Also, I got the O2 sensors relocated to right after the header (came with no o2 bung) and right after the cat. After about 25 miles I threw a CEL. I thought this way wouldn't throw a cell??? Also, will this CEL effect gas mileage (I will get it read soon just to make sure what it's throwing)?

Thanks.

[joph09]

What kind brand of header did you get? Yup adding a header will make it buzz best way to mellow it out is to throw a resonator or glasspack on the test pipe, also a catalytic converter will help with sound too. What type of resonator, any. For the O2 sensors the first one should be right on the collector or on the downpipe. The second O2 sensor should be behind a catalytic converter of your choice, seems magnaflow's highflow works fine to get rid of cels.

[ArunSenior04]

Details on your exhaust?

[TheHybrid]

I have a 4-2-1 long header from "something" performance (forget the name, my exhaust guy got it). No first cat. 2.25" piping leading back to the high flow cat (brand unknown, I didn't care).Then 2.25" piping leading to a magnaflow 3 chambered muffler.

[slow 2K2GT]

To get rid of the CEL you should get a spark plug non-fouler and install it on your 2nd o2 sensor. As for the buzzing from the install thats normal like joph said just get a good resonator or glasspack and have it installed. I had an 18" cherry bomb on mine and it worked fine.

[BColeman]

1) Make sure the 2nd O2 is 14" behind the cat.

2) A resonator, any style, will help to muffle that buzzing sound.

3) It will grow on you, the sound that is. I've gotten used to it after 2 years. Though I do have plans to change the exhaust a little to make it sound throaty.

4) Take your ride to an auto parts store, Advance or Autozone, and have them read the code, so you know exactly what is wrong.

[TheHybrid]

Thanks for the replies.

I think I'm gonna shower, eat and then go to advanced auto parts. I'll have them read the code, and clear it (won't stay away, I know). Then I'll take it down to midas or monroe and see who can put a resonator on for me (it's sunday, dunno if they'll be open). I hope to get it to go away soon. If not away, just stifled. It's just too loud to drive thru neighborhoods late at night.... and ricey.

Oh, and also.. If they can put it on today, where should I tell them to put it? Post-cat?

Alright, I'm back.

Midas/Monroe were closed so I went to Goodyear. They didn't have a resonator for my car (OEM or aftermarket) so I'm going to go to midas on my back tommorow.

As for the code, it's as suspected:

P0420 - Catalyst Efficiency Below Threshold

I did not clear it. I may reset the ECU later today. This is on an '03 model. I assume it won't effect gas mileage.

[jayupark]

ditto on the spark plug fouler (or you can buy an O2 sim on ebay)

[BColeman]

Resonator after the cat, that's correct.

Before you go adding in the de-fouler thingy, are you sure your second O2 is 14" past the cat? Are you sure both O2 sensors are plugged in?

Also, did the new O2 bungs get welded to the outside of the pipe, or did they sink them into the exhaust pipe. Sinking them is the proper way to do it to ensure the sensor is fully in the exhaust flow, and not half way in.

[TheHybrid]

Resonator after the cat, that's correct.

Before you go adding in the de-fouler thingy, are you sure your second O2 is 14" past the cat? Are you sure both O2 sensors are plugged in?

Also, did the new O2 bungs get welded to the outside of the pipe, or did they sink them into the exhaust pipe. Sinking them is the proper way to do it to ensure the sensor is fully in the exhaust flow, and not half way in.
Well, I'm not too worried about the CEL. The guy that did the re-wiring told me he'd inspect my car for me. Also, if I really wanted to, I could just reset the ECU outside the shop before I get it inspected. More worried about gas mileage (which this CEL won't hurt), but I'll fix the CEL eventually.

I'm going to Midas or Monroe tommorow after practice before work to get a resonator. I'm hoping a resonator will take out the buzz and mellow it out.

[BColeman]

A CEL in relation to the O2 sensors will make your car run richer, which enivitably leads to poor gas mileage. I've had CEL for 7 months now, the front O2 is bad, and the best gas mileage I get on the highway, if I'm lucky, is 27. In town, 24.

The CEL is a big deal, trust me. Once I replace mine, I'll have no problems anymore and get better gas mileage.

And that resonator will help quite a bit in quieting down the tinny sound of the exhaust.

[silversharkXD2]

if your header is from "something performance", it's no wonder it buzzes. The obx headers I bought of yamaha buzzed like hell. I've never heard anyone complain about buzzing from more expensive headers. Check the flange against the motor and make sure there are no leaks. the set I had had a chunk out of the flange and most likely contributed to the buzz due to the exhaust leak. But then I sold the car a week later, so I never tried to fix it.
BTW, you should always know what someone is putting on your car. There are some really fake headers even cheaper than SS autochrome on ebay. I'm willing to bet those kind wouldn't last a week. You should always get info and ask to see the packaging if you have to. I would never let a mechanic provide a part like that without proof of what brand it was. Is he willing to return it if it goes bad in a week, or will he warrenty it? I'm happy you got some parts put on, but you should always have as much knowledge about your car, and what is on it, as possible.

[TheHybrid]

if your header is from "something performance", it's no wonder it buzzes. The obx headers I bought of yamaha buzzed like hell. I've never heard anyone complain about buzzing from more expensive headers. Check the flange against the motor and make sure there are no leaks. the set I had had a chunk out of the flange and most likely contributed to the buzz due to the exhaust leak. But then I sold the car a week later, so I never tried to fix it.
BTW, you should always know what someone is putting on your car. There are some really fake headers even cheaper than SS autochrome on ebay. I'm willing to bet those kind wouldn't last a week. You should always get info and ask to see the packaging if you have to. I would never let a mechanic provide a part like that without proof of what brand it was. Is he willing to return it if it goes bad in a week, or will he warrenty it? I'm happy you got some parts put on, but you should always have as much knowledge about your car, and what is on it, as possible.
He doesn't have a specific warranty, but I know he'll repair what he messes up.

For instance, my exhaust contacts my right rear stabilizer. I talked to him about it and he told me it isn't bad, and won't injure anything as it's a small tap, and the exhaust will bend before the gauge steel bar. If it happens, he said he'll replace the exhaust, and find another way to rig it up. Also, he said if I drop the car, he'll fix it too (so it doesn't contact anything).

EDIT: As for now knowing exactly who makes the header... I merely asked him for a long 4-2-1 header and he provided. He assured me this fits perfectly (after ordering 3 other headers he said did not fit well enough). Perhaps I should have told him a brand, but to be honest, since I wasn't going turbo I wasn't too worried about it.

[silversharkXD2]

:worthless fair enough. Take pics

[TheHybrid]

Sorry, I don't have anything to take pictures... No camera phone or camera. Maybe I'll get one of my buddies to take more pics for me.

Also, why is it 14" after the cat for the 2nd O2? I'm just curious as it doesn't make sense why there'd be less carbon there than right after the cat... Are reactions still going on eliminating the carbon?

[saturn]

I'm getting 22mpg now... and my O2 sensors are fine :(

[Silentwolf]

I with Saturn tho most of mine is in town and im only getting 23mpg or so and i'm still stock on exhaust and header.

[evan938]

****...i had KEY MOTORSPORTS header and that ****er buzzed like a bumble bee. its not the header, its what you have after the collector. no cats + no resonator will be horrible. i think w/ my whole exhaust set up on my old XD, there was 1 cat, no resonator. key header, midpipe, cat, catback, older style EF exhaust cannister.

but it did give it a good amount of HP

[TheHybrid]

The header is GT System... Wow was I off. I'm dumb. My exhaust guy said he got it off some korean kids that race and he helps them with cat-backs and stuff. Says it's straight from china and "fresh off the boat" hahahha

Went to Midas/Monroe and they said they didn't want to touch my exhaust because everything's welded w/o flanges. I guess I'll take it back to where I got the exhaust done at.

I also checked the positioning of the o2 sensor. It's right after the cat. Whenever I get a resonator installed, I'll also get the o2 sensor moved 14" past the catalytic converter. Hopefully that will kill the CEL. If not, I'll use a de-fouler.

Also, does mid-pipe=resonator?

[Cypher]

was it nessecary to put "key motorsports" in caps? lol

if you have a straight with no restrictions and a fart can its going to buzz! simple as that

[TheHybrid]

was it nessecary to put "key motorsports" in caps? lol

if you have a straight with no restrictions and a fart can its going to buzz! simple as that
I have a high-flow cat, and a magnaflow 3 chambered muffler (I believe it's 3 chambered)

[TheHybrid]

Little Update:

Got my resonator installed and o2 sensor moved 14" away from the first (and only) cat. EDIT: Guy only charged me $40 bucks too. Was happy about that. He said it would cover just the parts, and he'd do the labor for free.

Car sounds much better. Has kinda of a chuga-chuga noise, but also a low growl. It also is back to sounding like sex at WOT.

Once I picked up the car, the CEL light was still on obviously. I wanted to go to advanced auto parts to clear the code, then reset the ECU, but autozone/advanced auto parts were both closed (9pm). So, I took the car home and just reset the ECU. We'll see if the CEL comes back on.