OK first of all, truck is a 97' 4X4 auto with 4.6 litre, 91K miles.

For a while now, my truck has had a hesitation problem.
Every once in a while, the idle will get very rough. (losing 2-4 cylinders it feels like) Once in a great while, that hesitation will appear during low throttle acceleration. If it does this, I floor it and it snaps too attention.

I changed plugs and wires hoping this would cure. No go.

The two middle plugs on the passenger side bank had oil in the plug holes.
(none escaping down threads)
Truck runs great after plug and wire change, (just like before really) but the intermittent miss is still there.

Also, I suspect a bad catalitic converter due to a rattling noise under truck after revving the engine when engine has been working hard.
(sounds like the hunnycomb is all broken up)

Anyways, last night during a 350 mile return trip home from Arizona the check engine light came on. Had Auto Zone pull code:

"powertrain: p0133, 02 sensor circuit slow response (bank 1, sensor 1)"

Truck continued to run fine. (no miss or hesitation during return trip at all that I can remember)

I purchased from A.Z. a new fuel filter, and a cleaner for the MAF sensor. Will do both tomorrow. The CEL went off on the way home from auto zone.

Any advise on the engine hesitation, and/or check engine light appreciated greatly. Could this all be due too a failing catalitic converter?

 

Any Ford techs out there?

 

bank 1 sensor 1 is the pass frt sensor,do not buy aftermarket sensor this will cause a hesitation,i also believe there is a pcm update for that truck which may help,you also may want to take it somewhere and have the injectors power flushed and clean the throttle body