You have a vented hood that is obviously letting water into the engine bay and you didn't mention that to begin with? Perhaps you should swap the stock hood back on? It's aluminum and weighs nothing to begin with, I've never understood swapping for a carbon hood on the s2000. Even a vented hood will be worthless unless you are tracking the car, which it sounds to me you are daily driving it.

 

The acceleration pedal position sensor is screwing with u. It's probably gone.

 

the pedal position sensor is brand-new you think is really gone (AGAIN) the car is running perfectly fine right now the only thing is that it acts up when it rain or wash it and a lot of water goes inside the engine bay.....

my car is a daily driver at the moment but I'm already getting my second car by jan. or feb and my car is only going to be use for track use.

 

I know this is an old thread but this is for reference for anyone who has CEL p2138 or if you have DBW and car is jerking when letting off. A new Accelerator Pedal Position sensor fixed all it all and also made my car feel a lot more smoother.