I have had the problem with the OBDII port not reading and the gauges not working, But everything is working fine on the car except for the gauges, The speedo and oil press were the only gauges working. This has happened during an engine change, but I cant think of any wires that it could be. I know that the ground wires on the back of the heads can cause this but they are plugged in. Whatelse could it be?

 

The pcm is losing serial data communications. The gauges are serial that is why the speedo and oil pressure are the only ones working. You need to check the grounds real close. Then at that point determine if the serial communications wire from the pcm to the aldl may have a short to ground, power, or open circuit. DVOM with all modules unplugged off of the buss will help you determine what is happening.

 

Thanks alot Ill deff try that.