i have a mitsibushi lancer 1600 factory fitted cng .. its done 80,000 kms ,, the cars in perfect condition , recently ive encountered a problem with its rpm dropping on petro and cng when the ac is turned on ,, showed the car to a mechanic and he said that a new throttle body is required ... is it this problem if yes then how much will it cost me .. ad new one costs more than 60,000 ..any feedback is welcome