Hi po!

Planning to modify my exhaust system. By the way My ride's Honda City TypeZ 1.3. So far po ang napalitan ko pa lang is yung air intake, got the simota a few weeks back, haveplans to change the filter to knn but in the future pa naman... as of now po, i'd liketo change headers, downpipe and a free flow muff (for the muff, i don't know if you'll call it a free flow muff, has a 2" diamter, had the tip change nung wala pako totally background about cars) will the I/H/E mod help me gain more torque HP kahit konti? is it worth my money? kaya nagdadalawang isip din ako baka wala naman mangyari if i do the mod... may nagsabi kasi sakin na dont waste my money for the mod instead invest for an engine swap... i need your advice mga sir...