F-150 XLT 5.4L V8

• Automatic transmission
• 150,000 miles

Well I had this tinging noise when the engine was started, but I didn't think much of it. the truck is in fairly good shape and I was on leave driving from Louisiana to San Diego, Calif. The truck gets about 19 on the highway, and when the check engine light came on. I was getting about 13, a very noticeable difference. well I took it to a shop and they said it was my O2 sensors went out. so I spent about 200 dollars replacing them, well the light came on again and yet again the same crappy gas mileage. I eventually found out that one of the exhaust manifold bolts had broken, causing the noise, but also, air to be sucked into the exhaust, hitting the O2 sensor, reading that the engine had too much air, which caused the bad gas mileage. well I also found out that ford is the only company to make such bolts. which are about 12 dollars a piece. for a friggin bolt! well I also found out that they are week and all break. well I finally fixed the problem leading me to spend about 600 dollars to fix. And I noticed, almost every ford F-150, made that same noise that mine did when that exhaust manifold bolt broke. so if you hear that noise, check under your truck or have some mechanic do it it might just be that bolt, I've heard at least 5 a day for the past 8 days making the same noise, so I think it's more than just coincidence.