While these little gadgets seldom need cleaning, engine performance often improves greatly after cleaning one that needs it. My old pickup had developed an annoying ping on acceleration. Knowing I had done a tune-up just a few months ago, I thought perhaps the EGR valve was going bad. Then I discovered these newer Tacomas don't have an EGR valve. It finally hit me that it was probably time to remove and clean the Mass Air Flow Sensor. Just a few squirts of cleaner and the problem is gone. I also made it a point to clean the area where the sensor attaches to the air filter outlet so that it would get a good seal. It's my understanding that leaks in the air intake (to the engine) system can be like chasing a bad ground on trailer lights where you spend a lot of time trying to find the problem.

Good to know.