first of all I have a 2003 duramax with about 29000 miles on it. New injectors, 4" exhaust, PPE boost vavle and K&N Cold air intake.

The truck went into what i am guessing is limp mode this morning ( would not let my RPM get somewhere over 1800). so i turned it off and back on still done the same. so I had to get to work another 3 miles down the road and it would not get over 25mph. so i made it to work and called my mechanic to come get it. went out with the keys and it started right up ran normal but the fuel level gauge was showing E, but I am sure that it has atleast a half tank of fuel. called the shop and they said it was showing two codes P0202 and P0203.

 

http://www.edgeproducts.com/product_...cle-pdf-40.pdf

a list of all gm codes