mgccfx4

I have a 2002 fx4 f150 and it has been the best truck. i just rolled 100000 miles and started having what seemed like fuel or air related rpm issues. the auto parts store handheld computer said misfire in cyl. 7 and misfire @ 1000 revs. so i changed all plugs and coils. didn't fix it and now the service engine light is on but the problem isn't constant. dealership wants $125 to diagnose with their computer but, for that much, i could replace at least 2 of the air or oxygen sensors. what should i try first?

02flaresidesport

my 4.2 needs an 02 sensor too. I have 128k its an 02 also. Mine was doing the similar thing.

farmerboy3

can't be that because my truck need's a new 02 sensor it runs fine and strong

02flaresidesport

mine through a code, but it also needed a tune up and a coil pack.