Dude Nakal u got the same ride as mine, btw what year is your car?
mine is 98 wira a/b 1.5 auto.
Here's what i did
1. exhaust 4-2-1, de-cat already replace with bullet ajusted to middle(for some reason the tuner guy say is good for pickup) and lastly an aftermarket muffler(s-flow). Piping i not sure of changing any advise?(currently 1.5 inch i think)
2. change to bigger throttle body (perdana v6 one) not very sure can use but my car is fine still moving:_: . After changing took it to my frens place for ecu tuning.
3. Took out the snorkle u shape thing at the air filter box. Mayb u can change to an after market air filter K&n or apexi.
4. Result of all this mod, better pickup and power than a Stock auto 1.5 (pros)
5. Fuel consumtion like sh!t rm50 if lucky can go up to 170km - 190km (Cons)