O2 sensors on the s2k are very fragile. Slight tugs on the wires or gorilla wrenching will damage the o2 heater circuit, which I'm sure that's what your code is for.

 

Hello fellow s2ker"s, I'm new to the forum but got my street legal go-cart last May! Just installed an invidia q300 cat-back exhaust on my ap1 s2k.... Took me about two hrs in my driveway with limited tools and novice mechanical skills and no CEL! Installed k&n intake a few weeks ago and the combination sounds amazing! Would highly recommend both to anyone looking for these upgrades.... Heightened throttle response and torque, don't know the difference in times there would be on the track but there was definitely a noticeable difference on the street...

 

I am a big proponent of the K&N fipk. Very hard to beat bang-for-buck.

 

I did a dyno back to back and 0.00 HP gain with the k&n intake. The stock intake system is very efficiently designed.
Yes k&n sounds good but that's about it.

 

Really -- did you drive the car for a bit once switched I read somewhere that the car has to learn it first before noticeable gains are achieved--oh knows may be a bs line I read. Like you said at least it sounds good.

 

Maybe so but it also looks good under the hood... very clean and almost a factory look to it! I also have been driving my FJ Cruiser for the winter and haven't driven the S for a while so maybe it was just the thrill of driving it again and anticipation of the wicked sound from the new exhaust and intake!