Bought this truck from my work about 2 months ago. It was a trade in. Got it for $750. Ots a 94 K2500 long bed with a 5 speed. Awesome truck! Love this thing and dont ever wanna get rid of it. When I first bought it, it was pulling a code 29 for faulty glowplug relay and code 31 for wastegate solenoid. The wastegate solenoid was bad so I replaced it and it fixed that issue. Then it popped up with a code 36 but still had the 29. Wasnt totally sure what to think. It's now showing code 29, 36, 49, 57, and 62. The pmd is relocated to front bumper and has aftermarket 9 blade engine fan as well as straight pipe exhaust. No other mods yet. The check engine light sometimes comes on and then goes away. It does this intermittently almost everytime I drive the truck. Usually after its warmed up itll only come on at high speeds. Sometimes it wont come on and off at all. When I comes on, itll stay on until I decelerate then go off till I accelerate to a certain speed again. Last night, the truck bucked about 3 times. Never done that before. It did miss a few times at idle a few months ago but has been absolutely perfect since. And in the mornings even when it's not cold and I go to start it up, itll smoke white/blue/grey for about 10-20 seconds and then be fine. Done that since I bought it. If I hit the accelerator itll go away quicker. Any ideas? Truck has 195k miles.