Funny thing happened today. I finished installing my replacement Fujitsubo exhaust, reset the ECU and fired up the car to re-learn the fuel trims. Within 30 seconds the TCS light came on and then a few minutes later the CEL came on. The car stumbled and idled funny as it warmed up. I cut the ignition and re-started the car. This time, both TCS and CEL were on instantly. Took the car for a quick drive and it was sluggish- almost felt like it was running on 5 cylinders. Also strange was that the idle stayed at 1,200 rpm fully warmed up.

Shut the car off and jumped the service connector to pull the codes. When I turned the ignition on to check the codes, the CEL was gone and TCS was gone. Pulled the jumper out and fired up the car. No lights and idled totally normal. Took it for a spin and my NSX was back to normal. It was snowy on the roads, so I was able to test TCS and ABS and both worked normally (new ABS is awesome btw).

So, um, what gives?????