Could be the TPS...it's a cheap part ($25) so I'd replace it anyway.
I dealt with a 1993 Ford Escort that was giving a code that means something similar to P1121 -- problem turned out to be two things: a vacuum leak (someone replaced the PVC hose with heater hose and it didn't last long with a 90 degree bend and split) and a messed up mass air flow sensor (had a piece of hair on the sensor wire).
I could have removed the hair, but I just got a $25 MAF at a wrecking yard.
