did valero brand gas make my check engie light come on?

[thstone]

Anything is possible but its not likely that the gas caused the CEL. More likely is that you purchased a car with an issue known to the previous owner (who ignored it and cleared the CEL long enough to sell the car).

Owners manual says that a constant CEL is driveable, flashing CEL is not driveable (pages 78/79). Since you got both, I'd go with the more severe (not driveable).

If you have a code reader (or can borrow one), use it to read out the codes and post here for further advice.

If you don't have a code reader or can't borrow one, then I'd trailer it to a local shop for diagnosis. Driving it further at this point could create more damage.