Hello again..I notice that my Truck is making a tapping sound on low rpm idlling but when I drive it I can hear louder when press the gas and if I left my feet from gas the tapping goes away I'm using MC filter what I have to check?

 

Are you sure it's not an exhaust leak?

 

I'm not sure I heard that can be exhaust leak or loosen spark plugs...what is the best way to check for exhaust leak??