What specifically is 8888 mean P0420 Saturn -

Question

Odi11 engine code tester reads out 8888 can you pin point more specifically what the problem is

Answer 1

8888 when a scan tools is connected to your vehicle ECM the scan tool trys to make contacts at your vehicles ECM communication protacols. When 8888 is on a scan tool this is windows communication or its end point.in communication using binding. it does not represent a problem with the vehicle is just the communication is complete.

Here is scan tool searching for a communication of the vehicle until it matches

Here it is still searching for a communication

Scan tools will use a variety of communication protacol  in its software until a communication with the vehicle is established