I have a 1991 GMC K1500. Its a 350 tbi. I just replaced the fuel pressure line/return line from the fuel filter to the throttle body. (new filter as well) The truck now runs terrible, and the exhaust smells like gas. not exhaust. The truck shakes really hard while idling, and dies when i put it in gear. going down the road, the truck sounds like it is misfiiring, and shakes really bad. none of this was happening until i changed those lines. and help would be appreciated! thank you!