I have a PR3(obd-0) in 91 teg. and I cant get rid of a CEL for code 21(vtec solenoid). I checked the wiring, and even rewired it and it wont work. could the 2nd o2 sensor wire not being connected be the problem? I checked the vtec solenoid by jumping it to direct 12v and it works(clicks). I jumped it at the solenoid, and back at the ecu, all works. So the wiring is good, solenoid is good, but Ive tried 2 PR3's and I get the same CEL, so It has to be something on my car...?