Ive takin my truck back to the dealership several times for warrenty issues. (rear main, steering shaft and an axle seal) But lately Ive been taken it back for a PO442 code. Three times to be exact. Now the lights back on for the forth time. They have replaced fuel tank pressure sensor, gas cap, and the evap vent solenoid. Is there any thing else I can check before I take it back. My truck is an 07 classic ecsb 5.3 with an intake, shift kit and vette servo. Any help would really be great. I know warrenty is free but man its a pain taken it back.