Four problems related to manifold/header/muffler/tail pipe have been reported for the 2012 Ford F-150. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 Ford F-150 based on all problems reported for the 2012 F-150.
The exhaust manifolds warp and in turn break off the exhaust manifold stud at the rear of the manifold making a very large exhaust leak at the block where it meets the exhaust manifold this happened under normal vehicle operation on highways.
Manifold leak, chirping noise when accelerating.
Exhaust manifold studs. Design flaw of the exhaust manifolds on the F-150 ecoboost causing manifold bolts to snap/sheer, which in turn causes the manifolds to warp. This is causing noise, and possibly exhaust gases to enter the passenger compartment. Ford is offering a fix under program code: 17m05 for the f450/f550, but is excluding the other "f series" trucks which suffer from the same/similar issue. The issue was noticed immediately after an engine misfire began occurring (which is also a known issue). The dealership has quoted $1,400 to replace the manifolds and studs.
24,991mi: misfire when accelerating while driving. No check engine light. Dealer reported no problem found, no codes & made no repairs. 29,440mi: misfire when accelerating & going up & down hills specifically when in 4,5, 6 gear during both flat & inclined highway driving. This was while pulling an 8000lb trailer. No check engine light. Dealer found misfire in #1 & 4 and replaced coils & plugs in #1 & #4 only. Test drive still showed misfire, then replaced turbo boost pressure sensor. I was told that moisture had damaged the plugs & sensor. 35,214mi: misfire when taking off from a stop, during normal acceleration and going up hills. No check engine light. Dealer replaced the driver’s side exhaust manifold because it was warped. 37,164mi: misfire when taking off from a stop, during normal acceleration & going up hills. I saw this in acceleration conditions from 10-60mph without towing a trailer. No check engine light. Dealer reported no problem found, no codes & made no repairs. 38,577mi: repeated severe misfires while going up moderate inclines. Check engine light came on (first time this ever happened) & I had a reduction in power, could not get out of 3rd gear & my speed dropped from 65mph to 50mph. After repair had moderate misfires during major inclines while towing a trailer but no check engine light. 39,000mi: while towing a trailer, experienced series of moderate to severe misfires in waves – be ok for an hour & then go into a series of misfires for 3-10 minutes. Some were on hills, some were on flat highway driving. I had 5 occurrences where the check engine light came on during this drive. 3 of these were during a hill climb where I had a power reduction & lost speed. Vehicle stayed in 3rd gear. When I would get a series of severe misfires, misfires were so severe (without the check engine light on), that I could hear & feel the turbo kick off & on. .