Ok i have a EK9 and im running a 99 GSR motor. the ECU is a 99 SI! when the car idles it idles at 1k then raise's up to 2k then down. It will do it 2-3 times before it just stops! since the Si B16a is a single stage manifold and the GSR is a dual could this be causing the problem?

If that is the problem i was thinking about going to the Skunk2 Manifold so i can also use a AEM cold Air intake and not just some Filter

 

doesn' the 99 si have a different type of obd setup? i don't know how well that 99 si ecu is mating with the b18c1.

i'd lookin into a p72 if you can find one, or go with a chipped p28, and convert to obd1

 

Thanks for the help man. Im gonna go with a 94 GS-R ECU and the skunk2 Ecu Jumper to OBD1

Thanks again