Quote Originally Posted by babywag View Post
The MTX-L seems to work very well. I have both outputs in use, stock o2 sensor was removed, and pcm is being fed an analog signal from the MTX-L. Other output goes to EEHack via pin D27. $?
Don't have schematics here. What was D27 used for before? It's not recommended in the ford camps to replace the NB with a pseudo NB signal from a WB. In general, it adds a conversion delay and the ford eecs sample with an expected delay as it switches it's LAMBSE's back and forth. If it doesn't detect the mixture yet switch cause of the delay, it continues to swing the LAMBSE further than needed in order to detect a switch happening. Guys are always told to weld in a dedicated bung especially when they seem to be chasing tuning ghosts. I would think the GM PCM's work similar.