Im new to the evo x world (wife totalled our 05 STi so we switched) and with ~5000 miles on the car I started getting all sorts of "check engine", "serivce required" lights so I took it to the dealer. The car had also been basically useless power wise above 5500rpm which I didnt notice until after the break in period. The first code was a p1320 which has apparently been fixed by a reflash which in the process fixed the loss of power up top. That all seems OK from what ive read about the original tunes and the dealers having to reflash them. The one that concerns me is a c123c code which the service tech was shocked by. He hadnt ever had that code pop up. It was something to do with the g and yaw sensors but other than what the computer told him he didnt have any idea what it all meant so he just recalibrated the sensors and reset the codes. I guess my question is: has anybody else seen this code pop up and if so is there anything I should be concerned with? Id like to get the car tuned with some go fast goodies but if this is going to be an issue in a few months then Id rather get it all fixed under waranty prior to voiding said warranty. Off-topic: I noticed the paint was chiping off on both sides of the rear bumper where it connects to the body in the wheel well. Ive read that mitsu paint sucks pretty bad and its obviously a manufacturer defect, so should I just be expecting constant issues with the paint? I guess with the whole car in general?

Thanks in advance for all advice.