I am not sure how the engine management system determines the fuel and ignition on the Jazz but my thoughts would be you will not better the standard map unless the engine is extensively modified.
I would not think you will get any gains from re mapping unless you have really changed the fuelling and ignition requirements of the engine.
You need to determine where the restriction is in the engine. Is it the exhaust? Induction? Then your best gains will be removing it.
x2.
As John says, there is very little point in remapping your Jazz in it's current form.
I had a Dastek piggyback ECU fitted and mapped on my old Civic EP2. With just intake and exhaust mods, i didn't gain anything worthwhile from the map.
However after making my own custom intake manifold and fitting that to the car, they managed to tune it up nicely. In stock form the car produced 108bhp, but after modifying the complete intake and exhaust system and getting it re-mapped i saw 135bhp (25% more power than stock).
Unless you are drastically changing how the engine performs, you won't need a re-map.
The stock ECU will adjust fuelling to the optimum ratio itself if you only change simple things like an air filter or cat-back exhaust system.
Steve.
