I know there is a price difference but wouldn't getting your fuel mapping redone actually geet rid of the CEL AND make the engine perform better with the new header/intake/exhaust? I would think actually telling the computer how to use the new power would make more sense than "patching the leaky pipe with duct tape"..........

 

Fuel mapping doesn't have anything to do with a CEL caused by aftermarket headers for the tC. Right now aftermarket headers delete your cat. The Megan Racing header has a cat (or sorts) on it, but it's high-flow, so it still doesn't act as a REAL cat acts.

The reason the check engine light comes on is because of the secondary O2 sensor. The only function of the secondary O2 sensor is to monitor the health of the cat. Since you remove the cat when you remove the stock header and replace it with an aftermarket one, the secondary O2 sensor is being hit with a lot of things the cat is supposed to filter out, and thinks that the cat is bad - hence the CEL.

Remapping your fuel doesn't have anything to do with a cat or lack thereof - remapping the fuel, no matter how you do it, won't make up for not having a cat as far as the shecondary O2 sensor is concerned.

Using the spark plug anti-fouler "mod" to fool the secondary O2 sensor isn't a "band-aid"... it's not like temporarily duct taping something on when it should be welded or anything like that. Using the spark plug anti-fouler method with a cat-delete is just making it so that a limited amount of "dirty" air coming from a cat-less exhaust is hitting the sensor by basically not putting the O2 sensor directly in the exhaust output stream as it should be.

This will have NO long term effect on the car. Even if you were running with a CEL caused by a secondary O2 sensor - the car wouldn't run in limp mode or anything. The only purpose for the secondary O2 sensor on OBD-II cars is emissions. The only risk you run when running a cat-less header without running the anti-fouler mod is exposing the O2 sensor to a ton of junk and clogging/killing it prematurely. That and you've got to stare at a nasty CEL, and if you're in a state where you have an emissions check, you'll fail for sure wiht a CEL. (Not to say you'd pass with the dirty exhaust you'd have by not having a cat even WITH the mod).

Running a catleass header with the anti-fouler mod isn't dangerous to your car, and it's not a "patch." You're basically fooling a piece of electronic equipment, and doing so (in this case) isn't going to harm your car at all.

 

^yup he's right. Was the same deal with my eclipse, which i did the resistor mod to.


I wonder if the second cat (main one under car) will filter out enough for state emmissions?

 

From my experience that's not a cat... just a resonator. All of my Hondas have had them and they look exactly the same as the one under the tC. It's hollow with the exception of some baffles for noise cancellation and that's about it.