Ford F150 - limp home mode

what would make a 1999 ford ranger go into limp home mode? it was missing on 4 and 6 so we changed the fuel injectors, plugs and wires, egr valve, and the thing the plugs go into. we cleaned out the cataletic converters and changed one of the co2 sensors. it runs great now but has no power whats so ever, it takes a long time to rev up and to drive it, there's no power to move it. a friend plugged it in to his computer and it said "LIMP HOME MODE" please help

I know that you said that you cleaned out the cats. But it still sounds to me like something is clogged in the exhaust line. Just my two cents.

The computer will generally switch to "limp home mode" when there is a lack of input for the computer to correctly calculate the air/fuel ratio, this causes it to use a generic fuel and timing map.

might try checking the AFM/MAS or whatever measures the airflow on that engine as well as the TPS... start by reseating the connections, if that doesn't help maybe get out a multimeter and a repair manual and test them???

When you break a leg or one of your tires goes flat. he.. he....