Howdy, I just purchased a 2004 Eddie Bauer expedition with that wasn't running properly from a friend of mine that didn't want to mess with it. It was dying intermittently and the problem was the burnt relay in the fuse panel. I fixed it but now it's acting up again with a new issue. If it's idling it will miss and upon acceleration in the lower RPM ranges it sounds like a popping coming from inside the exhaust muffler. It also smells very odd... like a real rich mixture maybe. It almost sounds like popcorn popping in my muffler to give you a reference. Does anyone have a clue as to what could be going on? Also plugs were changed 10,000 miles ago and it is not throwing any codes.
Thanks in advance for your reply.

 

I just run it again and the exhaust actually smells like fireworks that have just been popped........ if you are familiar with that smell. It really doesn't smell like a strong fuel smell but it is a strong smell.