I have a 94 4.0 OHV ranger and I put a drop in K&N filter in my air box, and I'm getting a "Ghost" CEL when ever I punch on the gas, or do a hard pull when the engine is cold. The OBD-1 scanner reads a Lean under partial throttle, and a Rich at WOT. what would cause my ECU to throw those codes?

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1994 4.0L Super Cab Ranger, 2.5% Window Tint, 31x10.5/15 Tires, American Racing Outlaw II rims, Custom Cat-Deleted Dual Exhaust, Jet Performance Module, TBS, Air Intake, Orion HCCA 12.4 subwoofer, Pretty Auburn Babe In Passenger Seat.

Future Mods: Full Wrap Around Rear Bumper, 2" SCH. 40 Pipe Brush Guard, Paint Fiberglass Topper, Projector Head-Lights