[CRAZYHAWK]

Try putting this before filling up;
Chevron Techron Complete Fuel System Cleaner, 10 oz - Walmart.com

 

[CRAZYHAWK]

Any time a check engine light turns on, scanned with code(s) displayed, write it down immediately. Some auto stores will read OBDII codes and print it out for a hard copy.

Without posting any error code(s) and describing "such and such......", this can lead to second guessing that may create more unnecessary replies. For instance; describing a rich running condition may suggest any issue; leaking injectors, poor fuel from any brand name or no name brand, never changing air filter that's thoroughly clogged from years of buildup, etc.

I use this scan tool;
EDIAG YA201 OBDII Enhanced Check Engine Code Scanner for cars 1996 & newer | eBay
it load tests the battery and
does the short and long term fuel trims.