BINGO !!!
Say no more.
We were driving northbound from Florida last month, I fueled at a Royal Farms station (700 Annapolis Rd Suite 1, Gambrills, MD 21054, if Google Maps is to be trusted).
Filled up, and waited to merge on Crain Hwy:
The traffic flow was insane, I waited for what looked like 4-5 minutes. Never-ending, and everybody was doing a good 50mph, after speeding to catch up an endless greenlight.
Found an opening, gunned it to merge in, and the car sputtered so badly I thought that was it. It took it a good quarter of a mile to clear, then it went mostly back to normal but my knock detector (I use Torque Pro and the Hyundai add-in shows plenty of good stuff) was showing higher values throughout the tank of gas. Filled up with Premium after that.
I had five out of six injectors die under warranty after a fill up on NJ Turnpike years ago, the techs back then told me that everything inside was orange, but back then there were no sputters or anything - I just drove 150 miles and the car threw codes once in Manhattan.
On that one though, it didn't kill the injectors but I could clearly feel there's something very, very wrong.
No Royal Farms for me anymore, unless it's Premium, and here in CT.