The check engine light on my 1998 ck 1500 truck came on. this was checked with a code scanner.
comes up as an evap emissions code. the shop that i took it to, did the smoke test to check for leaks, none were found. have replaced o2 sensors and egr also vapor pressure sensor on the gas tank.
the tech at the shop said the pcm could have an internal short. this is a 1998 chevy truck , 63,000
miles and 4.3 vortec six. is there an update that might cure this problem.

crzybill