i got a 98 HX and i want a few more horses from her. i dont care bout gas mileage that much. i got a cold air on it right now and 2.5inch cat back exhaust. Split Fire Plugs, fatter wires, short shifter, 10 pound flywheel, and an under drive pulley. can i swap this HX computer with an EX computer for enhanced performance? also, what intake manifolds and heads are the best swap for this motor? any info would be great.

 

The EX ecu will not work for the HX. The cams are totally different.

As for an intake manifold swap, there is a problem you will run into. The HX has an EGR valve on the manifold. If you put an EX intake manifold on thereyou will end up with a CEL. I just had my intake manifold and Throttle body port and polished. I have the intake manifold back, but the guy accidently sent me the wrong TB back, so I have to wait til I get mine before I can install it in my car.

Also, running a 2.5 inch Catback may be alittle too big for this motor. I say 2" - 2.25" is the best, but hey I could be wrong. Also, what under drive pulleys are you running?

 

EX ECU won't work...

while the HX does feature VTEC, it's the lesser known/used VTEC-E, which is VTEC for the exhaust ports only, not exhaust/intake like the EX

you'd have to change the entire head for the EX ECU to work, effectively doing a mini-me