Customer states it's only to monitor the temp, rpms while towing, it is not changing the computer program at all. The Edge web page doesn't seem to show a device for that year make model. Would you take the customer at his word or make him remove it. It there a way to tell if it is changing the program at this time?
I generally require an EO label for a pass, but I will reject rather than fail if it's missing, because I don't want to FuPR the previous tech over for legally going the extra mile to determine that it was acceptable.
A missing or illegible APL (aftermarket parts label) does not constitute a failure....provided the parts can be confirmed as CARB approved or exempted by comparing the part # with EO listings or parts manufacturer log.
I always try to look up the EO# and then I use my label maker and print out the EO# and place it on the part or next to the under hood label so I don't have to look it up next time and hopefully don't get dinged if it goes somewhere else.
People are usually shocked when they find out I'm not a very good electrician.