ok now i have had a similar problem with a 93 civic dx with b18c gsr swap. when i was placing the head i used copper spray on the head gasket to increase strength and aparently some had dripped onto my camshaft position sensor causing an engine light and code easily detected if you know what your looking at on the scanner. it caused my car to hit the rev limmiter at 3200 rpms. . . i hope this helps you