This is a chevy s10 4.3L vortec 4x4, it went from running perfect to misfiring, rough idling, strong smell of gas outside of the truck. When I try to accelerate it misses and will not shift into overdrive because of lack of power and idles rough. The check engine light blinks which means a misfire but the truck never stalls, it is very hard to start some times though. I have had the computer checked and got that my o2 sensors no activity because of the dual exhaust I had put on many months before with no problems, ran just fine, and random misfire on #1 cylinder. another place pulled a code of PO442, (evap system small leak) I checked all vacume hoses and the only one cracked was the pcv valve. Fixed it same problem. Changed fuel filter and it was packed full of a dark gray gritty colored almost like charcoal. did a compression test for burnt valve it holds 168 pounds on #1 but the #1 plug had a orange spark instead of a hot blue spark. I changed the distributer cab and new rotor button, same problem. could my vacume leak be a faulty fuel injector or a cracked injector O ring? I pulled out all the injectors and they looked fine when I put them back in 5 fit snuggly back in place but I could wiggle around and pull out the #1 injector with no problem could its O ring that it seats in be bad and leaking air? I tried pulling cables off battery over night to clear computher but still running bad. We have it pin pointed to the #1 cylinder all others fire fine. Could this be a bad spark plug wire or evap canister be full of gas, or bad injector or injector O ring? Please help this is getting agrivating and very expensive! thank you.