1992Vortec

Hey guys i know this isn't exactly a power adder question but i do have a a turbo lol. So i just got done with my engine reseal job to get ready for the summer. ended up needing a crank but thats a story for another day. I put in a 2 range colder plug and replaced plug wires but im now throwing a code 42. i currently have the MSD pro billet dissy that turns out to be junk when it comes to the module. a few questions on this issue will a colder plug play a roll in throwing this code? and or plug wires? also i still have the stock dizzy can i use that module on my MSD dizzy? only thing i can tell is the pickups look different. The code is intermittent and only seems to come on when at idle or low rpm situations. ive ran thought the flow chart with everything checking good at time of test.

Thanks, matt