How Do I Fix Code P0421?

How Do I Fix Code P0421? How do I bypass a P0421 code? It SHOULD fix P0421. -purchase 1 package of 2 spark plug anti foulers at your local auto parts store. -disconnect the negative terminal on your battery. -screw the drilled spark plug anti-fouler on top of the original. -jack the car up or … Continue reading How Do I Fix Code P0421?