I have a 96 Impala (OBD2). I am using Alex Peper's scanner. The scanner would connect fine before I got a custom tune.

What possible changes in the custom tune would cause my scanner to no longer connect. I have asked the Tuner and he is pretty sure that nothing he did would have caused this.

I even bought another PCM with the OEM tune on it. Hooked it to the car and scanner connected fine. Had the tuner load the custom tune on this PCM and scanner no longer connected. Went to Autozone and their scanner won't connect either.

To further confuse the issue, the tuner has a Tech2 scanner and it connects fine.

Thanks for any help. I'm stumped.