usdm 98 h22a4
type s cams and aem gears intake 2+
greddy header
2.5" piping stock muffler
aem cai
6puck clutch
11 pounds flywheel

when i used usdm ecu, it made clicking noise from the valve.
when i used jdm ecu, it made no noise and run like champ.

any idea?

 

i just experienced this same thing, but totally opposite. With my JDM p13 my valve ticket really bad, i put in a USDM p14...no ticking, was perfectly fine. It had something to do with the difference in timing between the 2 ecu's I had my timing really advanced and it was causing me to detonate with the JDM p13 but not with the p14. So i just turned the timing down and the ticking was gone. I am not sure if that will help. OH and the p13 was making me fail emissions really bad until i turned down the timing and seafoamed it. Then i passed with flying colors and the car is so smooth!

 

it's probably in the fuel maps. the jdm runs a little higher compression than the usdm, but the ignition maps are the same. that ticking you heard is probably detonation. When you put cams in, you're allowing more air into the cylinders without changing the amount of fuel. you can get larger injectors, tune your car, or just retard your dizzy a little, and the ticking should go away regardless of which ecu you use.