i need advice but get ready for a blog post
my car is getting terrible mileage (8mpg when it should be 15 city) and i'm not sure whats causing it.it
is also running a little louder than normal. i recently went on a trip to yellowstone and the problem cropped up then. here are a list of potential issues:
1. the bumpy road i went on somehow misaligned the muffler. (the road was so bumpy that the dome light that normally didn't work decided to turn on after a large pot hole).
2. i replaced the spark plug recently, but the car is not producing any codes. the spark plug wire has a hole that is wrapped with duct tape.
3. the cold weather and stop start conditions are causing a drop in mileage.
when i completely disconnect the wire, the misfire becomes obvious and the engine shakes. but when it's connected the problem (seems to) go away. Even when the engine claims that it's not misfiring the car just feels like its running louder than it used to when i first got it a year ago. i don't know what the best path forward is. i'm thinking of replacing the plugs, wires, and coil pack but that's going to be a few hours and i figure maybe one of you guys might have run into the same thing before.
pic related is car. 2006 Ford Ranger XLT 4.0 v6 4x4