So it getting cold out so i decide to get my friend to help me install my new spark plugs & wires on my 2005 v6 stang. I went with the NGK 7159 TR55-1GP Single Platinum Spark Plug & the taylor street thunder 8mm spark plug wires. Before we install the new wires & sparks everything was fine but take it when we pulled out the old spark plug they were on there last leg. Anyway everything went well besides three things that concerns me. For one we didn't use any anti seize nor any dielectric grease on the spark plugs & wires nor did we space the spark plugs. After i left his house i notice my car dropping in rpm from 750 to 500 rpm while stopped at the light but is sounds like its gonna stall on me. Also Im hearing a weird humping noise coming from the muffler. But while Im driving its fantastic. I notice a improvement in throttle response it just when im idling that really has me concerned. Oh & also we didn't space the new spark plugs either but where gonna do so tomorrow to .65. So plz ANY insight would be great

 

Boss....check your wires at the coil. There are 2 wires that are out of normal order that one would think they should be. They are reversed. Other than that, you may of knocked a vacuum hose loose, or disturbed something, causing the drop in rpms. Basically, double check your work. If it worked before..... Good luck.

 

Its been raining for the past few day so I haven't been under the hood yet. But last night when I got off work I made the stang relearn idle...ac max while idling for five minutes ac off while idling for five min then I drove ten miles on the highway. I drove home park the car an got up the next morning with a check engine light on. I never been so happy to see it in my life lol. Took it to advance auto to diagnose an what do they find? Mis fire cylinder 4...FINALLY I can drive with peace at mind again

 

What caused the #4 misfire? Was it the plug or the wire? Here is a pic of what I was describing. Look at the coil. 5 & 6 are reversed on the coil. #4 cylinder certainly couldn't of been what I was saying, but thought that I should clarify for some people.

 

Wait so the smaller pic is the coil pack an the larger one is the engine itself right?