For some reason i cant pull the diagnostic codes on my 1995 GMC k1500. Any suggestions?

You likely have the OBD1.5. I think that'* the OBD1 plug and OBD2 codes. So you need the right scanner.

I've tried the paperclip trick and it wont do anything. The service engine soon light wont come on. The check gauges light and the battery light are the only lights that stay on when I turn the key on.

Do you have a OBD1 or a OBD2 plug? If you have a OBD2 the paperclip wont work.

I believe its an OBD1. Whats the difference? The truck is running rough, and has lack of power. I've changed the plug wires, dist. cap, rotor button, and coil. It starts quicker, but still running rough.

94-95 was a transistional time its not obd2, its not obd1 because the clip would work. you have to get a specific reader that says it does GM 1.5. did you change the fuel filter, check for 9-13psi, or look down the tbi at the spay pattern?

it really helps when there is a BULB for the service engine soon light! was able to pull code 12 and that was it. still running rough though. its got me boggled.

code 12 is system self check..After running for a short period of time check to see if your cat convertor is alot hotter than the rest of your exhaust..Also how is your fuel pressure?how many miles are on the truck

OBD 1.5 has the OBD 2 plug with slightly enhanced OBD 1 function. The correct scan tool will communicate.

There is no cat converter. Headers and Flowmasters, thats it.