DHRLAW

Hi Guys - my 2020 G63 recently got Renntech ECU upgrade, blow-off values, exhaust module and BMC air filters. All work done at reputable local tuning shop. Unfortunately, I have gotten a couple check engine lights and have taken it back for a scan (twice) but there is no code. A couple of times I got the check engine light on the 2nd re-start after refuel. Yes gas cap is on tight. And, now the light it on constantly. Car does not drive any different (i.e. not in limp-home mode). Any suggestions would be very much appreciated. Very frustrating.

Thanks,
David-