The check engine light began by flashing and now is steady state "on" and over time began running rough until warmed up and having hesitation during acceleration. Test at Autozone indicated a missfire in the #5 cilinder. I swapped the original installed plugs (#5 and #6) same problem. Then installed new plugs and wires with no fix. Then replaced the crankshaft position sensor and still having the same problem. This 97 F150 has 115,000 miles and has also started requiring water to be added slightly (1 qt / month) around the same time the check engine light started. There is no water leaking from the truck though. Anyway to fix the engine light what is the next step? A new coil or could it be a fuel injector? Thanks

 

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Hello Romeo, Welcome to FTE and the 4.2 forum!

Here's your answer-----

https://www.ford-trucks.com/forums/s...d.php?t=340552

https://www.ford-trucks.com/forums/s...d.php?t=348912

sure sounds like what is going on with your truck.