If you're going with a b18c5, make sure the ECU you'll be using is an AMERICAN ITR ECU, otherwise the ref will fail you on the visual. Basically, he will look over your car and make sure all the smog equipment is for a US ITR, or a part that is CARB approved for a US ITR. Once you pass the visual, they'll toss it on the sniffer and make sure it passes under the US ITR standards. So refs are more strict than others, but you can go back once for free, and retests are pretty cheap.