https://www.youtube.com/watch?v=RCWfSIq6FWc
Shop for New Auto Parts at 1AAuto.com http://1aau.to/c/27/q/engine-tune-up-kits Does your car or truck have a flashing check engine light? Has it been getting worse gas mileage lately? It's possible those two symptoms are connected, and you can fix both with new spark plugs or ignition coils! In this video, Len explains how running rich can reduce fuel efficiency, and set off a check engine light, and what you can do to fix both!