2002 Honda Civic engine fault -TPS

HI, I am from mauritius and my honda is a civic-vtis, second hand car imported from singapore. It is almost 2 years that I have it and I got an engine fault early this year. After scanning it was found to be a TPS(throttle positoin sensor) fault, Symtons are:the car starts hunting(erratic running), it looses power, thus I have to change gear. The engine rotating speed at neutral increases from 500rpm to 1200rpm. So I need to switch off the engine and start again to clear the fault on the dashboard and the car becomes normal. But this fault is not permanent, it may appear after one week or one month.A mechanic requested me to clean the TPS assembly with solvent that what we did. The fault then did not appeared for four months. It then reappeared and I replaced the TPS assembly by a brand new one. Indeed, the fault reappeared one week later after replacing the TPS.I dont know what to do now. An another mechanic is requesting me to check the wires and eventaully the computer control box.
Please help me.
thanks and regards.