missfire or bad cats?

[91rangerxlt]

I've got a 99 f150 with the 4.6 and driving down the hiway the check engine light started flasing, its been on since I got the truck cause of bad oxygen sensors, I looked in owners manual and it said it is a misfite, but when I plugged it in on autozones code thing it said the only thing is bad 02 sensor and bad cats, would bad cats cause this, its real rough idleing and ain't got much power, the light comes on only during acceleration. The truck has 252600 miles.

 

[91rangerxlt]

Any one??

 

[adsm08]

The CEL flashing generally indicates a catalyst-damaging misfire. If you only codes are for O2 sensors and the cats there are checks that can be done.

A miss fire generally presents as a bucking or vibration while running.

Drive it at night and then poke your head under it. If the converters are glowing.... well, go drive through a field with tall grass and enjoy the flames.

Then buy some new cats.

If they aren't glowing, replace your plugs, wires, and coil packs.