K20A2 Exhaust

[Princess]

Are you 100% sure you have a k20a2? That's the RSX-S engine until '05.

[talonXracer]

If your exhaust is not making any contact with the chassis and is not leaking then why mess with it?

The EP3 header/cat assembly is shorter than the typeS header and cat by about 3". This three inch difference is made up on the cat end of the midpipe.

Here is a pic showing a EP3 length midpipe, the red line signifies where the typeS mid-pipe/cat flange would be located at.



the typeS would have its flange just prior to the bend on the midpipe that is closest to the camera.

[Draw7Seven]

Ok, starting to make sense. Is there a diagram of the EP3 exhaust anywhere on this site??? That would be key. Basically, my check engine light is on for the primary O2 sensor. I want ot fix this and at the same tiem replace the filler piece. I have a Type S header and I need a what to hook up to the Cat?

You don't even need a diagram, dude. From the engine to the ass of your car:
-Header comes off the engine (stock headers are commonly called exhaust manifolds)
-Downpipe/Catalytic Converter comes off the header
-Midpipe comes off the downpipe/cat
-Axleback comes off the midpipe

One thing to realize about buying a part to solve your problem: if you're going to be continuing to mod the car for performance, look into a race header. RACE HEADERS REPLACE TWO PIECES AT ONCE: THE STOCK HEADER AND THE DOWNPIPE/CAT. They flow better because of the easier angling they make as they snake towards the midpipe and the elimination of the constrictive catalytic converter. To get rid of your CEL, you'll have to get an o2 sim (look it up). It sounds to me like a race header would solve your problems pretty well, but it will also make you illegal for emissions.

[talonXracer]

RACE HEADERS REPLACE TWO PIECES AT ONCE: THE STOCK HEADER AND THE DOWNPIPE/CAT. They flow better because of the easier angling they make as they snake towards the midpipe and the elimination of the constrictive catalytic converter. To get rid of your CEL, you'll have to get an o2 sim (look it up). It sounds to me like a race header would solve your problems pretty well, but it will also make you illegal for emissions.

There is no reason to have to run a race header with no cat. I have run a cat on both race headers I have owned for the EP3, a JRrh and a SSR tri-Y. Both accepted a universal cat with ease.

Sure I lost about 3-4 whp on top, but gained ALOT in the midrange and down low, probably 12-13 ft lbs of torque. That makes a huge difference on te street. If your car is a DD, it just doest make sense to loose power where it is used all the time.

[RedSiBaron]

Are you 100% sure you have a k20a2? That's the RSX-S engine until '05.

uhhh, he said he has stock usdm ep3 header on his k20a2, thats why it doesnt bolt up without an adapter...

There is no reason to have to run a race header with no cat. I have run a cat on both race headers I have owned for the EP3, a JRrh and a SSR tri-Y. Both accepted a universal cat with ease.

Sure I lost about 3-4 whp on top, but gained ALOT in the midrange and down low, probably 12-13 ft lbs of torque. That makes a huge difference on te street. If your car is a DD, it just doest make sense to loose power where it is used all the time.

werd to this mans knowledge...thats the route im going!!!

(thx again by the way talon )

[talonXracer]

uhhh, he said he has stock usdm ep3 header on his k20a2, thats why it doesnt bolt up without an adapter...

The stock EP3 exhaust will fit a K20A2 with absolutely no issues whatsoever!

Reread his posts, he has a typeS header and downpipe with a EP3 cat and specific catback. He had to have a downpipe adaptor made. The EP3 cat has a much smaller opening than the typeS head pipe and will create some flow issues.

And no problems, I try to help all if I can.

[RedSiBaron]

The stock EP3 exhaust will fit a K20A2 with absolutely no issues whatsoever!

Reread his posts, he has a typeS header and downpipe with a EP3 cat and specific catback. He had to have a downpipe adaptor made. The EP3 cat has a much smaller opening than the typeS head pipe and will create some flow issues.

And no problems, I try to help all if I can.

ahh, his post is confusing based on the first one, hadnt looked in a while and forgot his second post saying that, but all the same heh...yah it all bolts up...

[Cals si03]

What TalonXracer said is correct. So I need to buy what?

[talonXracer]

I would retain the custom setup as long as it isnt leaking. A custom piece is the same as rigged. Keep what you have untill you decide to go with a RH, then you will again have to "rig" "custom" weld your exhaust in order t have a cat.

[Cals si03]

It is leaking a little bit. If I get a race header it will hook directly up to my cat back exhaust?

[RedSiBaron]

It is leaking a little bit. If I get a race header it will hook directly up to my cat back exhaust?

yup it will...AS LONG AS YOU GET the same application header as the catback

if its a type s/itr/ctr catback get a type s/itr/ctr race header

if its a usdm ep3 catback get a usdm ep3 race header

and dats the troof

[Cals si03]

Sounds good. What about O2 sensors?

[RedSiBaron]

Sounds good. What about O2 sensors?

i believe you will need 1 extension, and the other will be a tight fit, if you run a race header and have a stock ecu you WILL throw a code...you can trick it with a 02 sim, OR you can get kpro...as talon and i have discussed, a raceheader without kpro is not going to get you the gains it could, and the whole 02sim thing and not running a cat confuses the shit out of the stock ecu (or atleast this what i thought you were saying doug, correct that last bit if its wrong, )


OH ALSOi have been screwing around trying to decide if i should get a second extension before my install just to be safe with my ITR header...anyone have any thoughts on this???