Gti For Me
Go Kart Champion
the car threw some codes;
P0300 – Random/Multiple Cylinder Misfire Detected
P0301 – Cylinder 1 Misfire Detected
P0302 – Cylinder 2 Misfire Detected
P0303 – Cylinder 3 Misfire Detected
P0304 – Cylinder 4 Misfire Detected
Either you have some bad gas since you just filled or injectors took a crap causing running rich/black smoke from tailpipe
Now if the car is not misfiring but runs good i suspect that your ignition coils are good.