Does it only do it at low rpm (1200 or lower), or only when you finally put your foot back on the gas pedal?
I have a 2nd gen. Escort LX with the 5 speed. I connected a pair of wires at one of the fuel injector connectors, so I could have an l.e.d. and resistor inside the car and visible to me as I drove; the l.e.d. flashes each time the injector fires. On deceleration the injectors dont fire at all if the engine rpm is about about 1100 or 1200 rpm. If I push on the gas -at all-, the injectors would come back on. So a bad TPS might cause the injectors to fire on deceleration, and that might result in "afterfiring", i.e. a 'pop' out of the exhasut system.