Post by 87toyxtracab on Mar 30, 2014 12:17:13 GMT -5
I picked up a little 87 pickup with a blown motor, I yanked it out and through in a spare I had in the shop that came out of an 86. It turned over and runs like a top but check engine light is on. I checked the codes and i'm getting a( 51 and 21) 51 is swich signal 21 is o2. my problem is the wiring on the truck side is all cali emissions with a four wire o2 sensor currentlu sitting under drivers seat be for the cat, the motor and its harness is federal with a single wire o2 sensor which is siting in the exhaust manifold unplugged. currently the 4 wire o2 is plugged in, and the truck is running in limp mode because of the o2 sensor. I've already changed o2 thinking it was bad but im still gettig the code. so how can i get a federal motor with wiring harness to run properly with a california emissions truck? the computer is california emissions in the truck. Any info would help thank you