Engine Miss
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Junior Member
Joined: Apr 2011
Posts: 13
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From: Liverpool, PA
Engine Miss
I have a 2007 F150 SC, 2wd, with a 4.6 engine. The truck has 73,000 miles and I’ve had it for 8 months with no problems. A couple of weeks ago I had a bad vibration but didn’t get any CEL. I wasn’t sure if it was the engine of something in the drive train. The next time I drove it, there was no problem. The miss quit and was good for a couple of weeks. All of a sudden the miss is back and much worse. The CEL comes on and the gas mileage dropped to about 8mpg. I took it to AutoZone and the scan showed multiple misfires on 3 and 4. He said it also showed an O2 sensor problem. According to him it was probably the coil. I bought one coil instead of the two he wanted to sell me. I figured it would be unusual for two coils to go bad at the same time, and if I changed one then the miss should be less. If that was the problem then I would change the other coil. There was no change. I bought a code scanner and it shows a 172 bank 1 rich condition, a 300 multiple misfires, and a 303,304 cylinder misfires. I also have a pending o2 sensor code but I don’t remember the number, it was a 21xx something I think. How do I check the coil? It also has white smoke coming out the exhaust at times and you can smell the raw gas from that. There is no overheating problem so I don’t have a head cracked. It's very hard to start and seems to run better at higher rpm's. I've tried dry gas but no change. Other than spending money I don’t have at a dealership, what else do I check? I didn’t see any vacuum hoses problems either.