You are going to get a cel no matter what if you get a header. There are several solutions for it. Amd gave you a link to one, I gave you the link to another. If you are getting the invidia then you should use the fix from my link.

 

Yes, the s-pipe and resonator don't have anything to do with the CEL. The light is coming on b/c the 2nd O2 Sensor(on the s-pipe) is reading high polluntant levels in the exhaust gasses. Its reading that b/c you are essentialling taking out the cat from the header. That's what those two mods are for. They move the O2 sensor out of the exhaust flow so that it reads "clean" air instead of dirty air. The s-pipe is just going to help the exhaust gases flow smoother down the pipes. The resonator is going to help get rid of the rasp. So yes, bring them the antifouler or the part we linked you and tell them to install it and unplug the battery for about 5 mins before you crank it up for the first time after installing the header.

 

Your link? Last time I checked we both linked him to the same product

 

I think im going to use that link to install the header myself and use the stock midpipe and buy a set of those anti foulers at autozone.

 

Cool, I did my install on my own. Really gives you time to be one with your car LOL and ____ed at Toyo for using gorillas to tighten all the stock bolts down But for the antifoulers. I'm just going to throw it out there. They are a hit and miss with the tC. Some people they work great for. Others have CELs right after putting them on still, and some are fine and then they will random put a CEL on at like say 100miles or 400 miles, or even 2500miles...just pure randomness. I'm not saying that to help the other guy sell his part, Im saying that so your prepared with knowledge going into your project and not to be disappointed if the mod doesnt work. Oh, and if you end up messing up your O2 sensor(s) I got my two stock ones for sale

 

Heheh I confused your link with sddykstr's :D