Hello all,
I used to own a 2004 Mazda 3i. I went to carmax today to test drive a 2015 Mazda3i Touring. The test drive went perfectly. The A/C was even strong, which is nice because my older 3i had a ton of issues with the strength of the A/C.

So, the problem. The check engine light was on. We asked the rep to take the car back to the service department and have it checked. We were not going to make a final decision tonight, so he could take his time. He tried to just sell his way out of it saying, "oh, I'm sure they just forgot to reset it after they changed the oil". He proceeded to drive it back behind the building for 10 minutes, then ran and caught us before we left to tell us "see, I was right. they confirmed it and it is fixed".

I'm pretty annoyed. I assume they just reset the light and called it a day. Does anybody know how long I should drive it next time to before the light may come on again (if there was an issue)? I can tell them I wont consider purchasing unless I get an hour test drive... or... should I bring one of those devices (PCB?) with me and assume that will diagnose any potential check engine issues myself?

The car may not have any issues at all, but the process annoyed me quite a bit and now I'm a bit skeptical. Thoughts?

https://www.carmax.com/car/16988024?...rpage_16988024