My mercury is making a popping sound when I press the gas and if I floor it , it dies I cleaned the sensor but it's still doing it someone told me its letting too much air in and the sensor needs replacing but I wanna get more ideas .

 

Any check engine light?

Dies at idle? unstable/rolling idle then it dies?

Could be intake manifold leaks as well..

 

The check engine light would come on then go away when I mess with the air intake and yes it dies at idle and ya unstable could it be spark plugs ? And if it is a leak how could I find it?

 

If you could have the code/s read its always good to have that info available for a better diagnostic 'direction'. Some of the aftermarket parts houses will read them for you at no cost.

Is the idle/stall condition worse when cold?

If you raise or open the throttle slightly, does the engine smooth? No engine misfire? Generally if the truck runs on all cylinders at cruise or moderate throttle, or harder throttle angles without a misfire, it's usually not plugs. If it has a rolling, unstable idle, and runs relatively good in the other ranges, I'd be looking at vacuum leaks, IAC, or air metering, but to have the code and the reason the CEL was on would be a big help.

If the code/s point toward a lean running condition, and it's possibly or suspected a manifold leak, you can take propane ect. and 'bleed it' at the manifold surface area to see if there any idle improvement. Carb/throttle body cleaner ect, will help help show a leak if sprayed in a problem area. As would ether, but is much more flammable and not the best choice, but doable if used lightly and with caution.

I use a small propane torch with a long small nylon whip hose attached. Easy to control volume and application/direction..