2000 Hyundai Sonata Misfire After Washing: P0304 and P0100 OBDII Codes Explained
After washing my 2000 Hyundai Sonata at 80,000 miles, I noticed a misfire shortly after starting the engine. No vacuum leaks were detected, and no water was observed entering the engine. The OBDII diagnostic system shows codes P0304 (cylinder 4 misfire) and P0100 (mass air flow sensor malfunction). I'm seeking advice on potential causes and solutions for this issue, especially given the timing after a car wash.
Consider switching to higher-quality fuel, as poor gasoline quality can contribute to misfires and sensor inaccuracies in older vehicles like the 2000 Hyundai Sonata.