Not sure if this will help, but thought I'd share this with ya... My'13 SS recently popped same codes approx 1/2mile after fueling up.
*I've had my CAI intake & Apex scoop nearly 2yrs.
*Solo Mach XL catback was installed last Summer.
Stock headers/cats. No tune. Never had previous issue or CELs.
Fueled up at same Shell station I've always used, & same fuel, "93 V-power". Had no difference in throttle response, noise, or hesitation... just steady Check Engine Light moments after pulling out of the station.
Did the obvious first: checked GM locking fuel cap when I got home, then cleaned MAF sensor next day. Even replaced stock fuel cap... Nothing cleared CEL. Took it to Carquest. They verified exhaust tight, cats looked great, & he didn't think it was O2 sensors. Cleared "lean" PO15B & D codes, advising he wouldn't doubt it was just bad fuel mix from station. Gave me a bottle of Lucas Fuel Injector cleaner, which I dumped in tank right away. When fuel was down to nearly 1/4 tank (same tank of possibly "bad fuel"), CEL popped back on again.
Headed straight to Chevy dealership in town next day. Tank was nearly on empty, so stopped to fuel up about 5 miles from dealership. Got back in car, fired her up... CEL was gone, all by itself!?!? Still had dealer change oil, & they ran diagnostic check to be sure... No issues found.
Have fueled up twice since then (at two different stations), no problems what so ever.
