exhaust question.

[Dragon_Reborn]

Will my car through a CEL if i remove the precat? I want a new exhaust b/c the one i have is rusted and falling apart, i would like some headers and 1 cat. and new piping (2.25") all the way back to a nice free flowing good sounding muffler. any ideas? suggestions?

 

[Matthew]

yes

 

[SilverBulletES]

Will my car through a CEL if i remove the precat? I want a new exhaust b/c the one i have is rusted and falling apart, i would like some headers and 1 cat. and new piping (2.25") all the way back to a nice free flowing good sounding muffler. any ideas? suggestions?

I got an OBX header a couple weeks ago. Replaces stock header and first cat.
We installed the "MIL elimiator" resistor.... didn't work.. 6 days later threw a CEL. Reset computer.... 6 days later threw a CEL.

But supposedly the "spark plug non-fouler" fix (search) is infallible. I bought one the other day ($3) but haven't had time to install it yet. However, no soldering needed-- just drill one out, screw one into the other, screw your sensor in.

I'm thinking I might not trip a light now though b/c I now have MP3 ECU which is more forgiving with emissions... we'll see. No CEL news is good news...

 

[DiS]

I got an OBX header a couple weeks ago. Replaces stock header and first cat.
We installed the "MIL elimiator" resistor.... didn't work.. 6 days later threw a CEL. Reset computer.... 6 days later threw a CEL.

But supposedly the "spark plug non-fouler" fix (search) is infallible. I bought one the other day ($3) but haven't had time to install it yet. However, no soldering needed-- just drill one out, screw one into the other, screw your sensor in.

I'm thinking I might not trip a light now though b/c I now have MP3 ECU which is more forgiving with emissions... we'll see. No CEL news is good news...

yep, I think that mechanical fix is better than electrical one. Although when I had my header on, I had the electrical fix (you can find info on it in HOW-TO section) it worked for me good, but once I will get my custom turbo setup ready I will have mechanical fix. but getting on point, if you remove the pre-cat, you will throw the CEL

 

[toucci]

the spark plug non fouler trick works great and is easier to install and remove than the mil eliminator. the only problem is clearance if your bung is in a weird location since it sticks out so far.

 

[Zaurusman]

Which headers don't remove the pre-cat? And what does a Protege with a header and no other exhaust mods sound like? Is it louder? I'm trying to keep mine looking and sounding stock; just want a little better oompf up hills in fifth. Does a header sound like a good idea for that?

 

[evilmonkeyMSP]

I've had my non fouler in for over 6k miles & no CEL

 

[Boston5761]

go with the Wagner Motorsports shorty header keeps pre-cat

 

[manofmacg3]

Wagner set up is perfect for those who want to keep 100% emissions legal and still want performance.
I went with the shorty header, 2.5" downpipe with high flow cat and their 2.5" midpipe also with cat. Good stuff.

 

[DiS]

Wagner kit is definetly good, but keep in mind as long as you have cats, you still have restriction, even if its a highflow cat. Definetly, wagner kit is great for emissions, but if you're in a state that doesnt require them, might as well get a straight through (just make sure to keep a resonator, otherwise your exhaust will be incredibly loud, hehe) (thumb)

 

[Zaurusman]

Thanks for the advice, guys! I think I may give the Wagner a whirl. I have to keep it emissions legal, and want to keep it quiet since it's my daily.

 

[Lord_Zath]

Does your state do a sniffer test? If not, then it all emissions testing will do is plug into the car's computer and check for a CEL.

If that's the case, I'd say get the OBX. Much more power gained since you're removing the first cat. You'll still have the second cat anyways so if they did a visual test, they'd still see a cat on the car.

The problem with the wagner like others have said is that you are still going into the first cat, so you really won't be adding much horsepower. You'd be better off spending your money on an intake, lightened clutch/flywheel, or an underdrive pulley.

 

[BlackMSP]

Eh I would just go with a catback, don't worry about a header, but thats just me =]

 

[DiS]

Eh I would just go with a catback, don't worry about a header, but thats just me =]

Header works wonders. It definetly adds more power than exhaust and intake combined, and if you have intake header and exhaust setup, its definetly nice. Im sure I would hit high 15's at the track if I would have full exhaust from header, but I only had mp3 axle back with few mods (header, intake, j-spec intake camshaft, UDP and few other toys) and I ran 16.03. Was kinda pissed because I was only .04 seconds away from hitting 15's but oh well, hehe, header shaved off .3 seconds anyways, so thats a plus. If you want to stay N/A and wanna get header, definetly get one, its worth it big time.

 

[Protege5 Driver]

pardon my ignorance but what is a non fouler?

 

[Lord_Zath]

A piece of metal that's designed to hold the spark plug higher up in the chamber so it does not become fouled, I believe. It's a temporary fix for that application. For the header application, so far it's been a permanent fix. The nice thing about it is you can simply unscrew the o2 sensor from it in case you have to go back to stock for emissions or something.

And I agree w/DiS - if you are bothering to upgrade your car's performance at all, a header should be at the top of your list...

 

[DiS]

A piece of metal that's designed to hold the spark plug higher up in the chamber so it does not become fouled, I believe. It's a temporary fix for that application. For the header application, so far it's been a permanent fix. The nice thing about it is you can simply unscrew the o2 sensor from it in case you have to go back to stock for emissions or something.

And I agree w/DiS - if you are bothering to upgrade your car's performance at all, a header should be at the top of your list...

what non-fouler does exactly, it helps to get rid of CEL that WILL show up on your dash after header instalation without any fixes (meaning by fixes, either electrical fix, like soldering in the resistor with capacitor into the o2 sensor wires, or non-fouler method) Anyhow, non-fouler is being welded to your header, in place where the o2 sensor goes in. Its basically a tube threaded on one side for the spark plug and has a small hole on the other side so the spark plug lead can make contant with inside of the cylinder wall. o2 sensor threads are the same as the spark plug threads so it all works out. What you do is, drill the small hole out to make that side of the tube the same diameter as the other side where the o2 sensor will screw in. Once this drilling/dremelling out is done, then you weld the non-fouler to the header and screw the o2 sensor in. What this does is, it keeps the o2 sensor out of the header so it wouldnt read the real amount of o2 which goes through the header, instead, o2 still reads the amount of o2 and temperature but since it is not in the header it doesnt read full temperature and cant send the signal to ECU so it would through a CEL. So there you have it, it permanently fixes the header CEL throwing problem. Thanks to fellas at WRX forums.

 

[showtege]

I went with the ractive Header it only has one O2 sensor hole on it. Then i used the stock MSP cat section and took its secound cat out. there is a 02 plug after the first cat. passes emissions perfect with secound cat removed. Then it goes down my ceramic coated 2.25in Hayame Cat back. Great low deap tone no ricey raspy sound.

 

[theice]

I have the wagner shorty and RB cat-back. What I want to do is get the Wagner DP with cat, then custom a straight catless mid-pipe. This setup should keep the o2 sensors in the same spots and I should be emissions legal without a cel.

What do you guys think?

 

[subsolo_21]

So if I want to get a header and keep the rest of my exhaust stock, how much will it change the sound of my car? I want my car to stay fairly quiet b/c I have to drive long distances a lot and loud exhaust gets old after a while.

Also does anyone have the Ebay Tsudo header. I doubt its as good as most others, but I'd consider one if they are ok.