Quote Originally Posted by Roland Jacques View Post
2001 GMC Savanana van 3500 5.7 litter.


Ill look at that thread closer.
The EFIE you purchased will work for your o2 sensors. They are narrowband sensors. Usually the signal wire for GM is purple. Test for voltage between
.1 - 1 volt engine hot and running. Voltage will constantly fluctuate up and down.