hi everyone , i decided to do the plugs and wires on my 92 seville sts today...i don;t know what i was thinking , i just should of had someone do it ..there is no room to get the rear plugs and not being a small guy it was even harder. the car was running perfect when i bought it which is about a month ago. but not knowing when the plugs and wires were changed last i figured i should change them , this way i know when they need to be done next. after doing the plug and wires and put everything back in its place i started it up just to feel a rough idle. i took it for a spin and felt like it was being held back and puttering . i have changed plugs before i know i didn;t do anything wrong .. what could it be??