You might also want to check the small hoses (i think it's the EVAP hoses) under your truck. They're located by the filler neck under your truck. I threw the same code on my 01 and it was the small hoses. They were dried and cracked pretty bad due to being exposed to the elements.

At least it's something you may want to check.....at least check the condition, so you don't throw that same code again.

 

p0442 is a crappy code to have. Yes it is USUALLY a gas cap; however, the code itself simply means tiny vacuum leak in the evap system. It is a very broad code. Ive found that gas caps from autozone, oriellys, advanced, xl parts, all SUCK. Buy the gas cap from the dealer. suprisingly its usually cheaper and better. Ive gone through a dozen aftermarket gas caps in 4 months. My dealer gas cap has lasted a year.

 

My malfunction indicator light was on...read on this forum to check gas tank cover and tighten it along with unscrew negative terminal on battery, turn ignition key to start and hold for 15 seconds turn off and remove it and then reconnect the negative terminal of my battery....did all that, the malfunction indicator light is no longer on, however, there is a chime (sounds like seat belt chime) that won't turn off as I'm driving and yes, my seat belt is buckeled...any suggestions would be greatly appreciated!!!