air filter service
 

Hi everybody, I purchased a 2008 ram 2500 diesel after selling my ram 1500. This is my first diesel. My question is my overhead chimed and now says service air filter, I checked it and the indicated was at the red so i pushed the plunger button and reset it and then open up the airbox to see that the filter really is not bad. So i dtart truck back up and message is gone, 2 miles later chimes again saying same thing and the plunger is in the red. Do these diesels really need a perfect looking filter? I bought a certified used and dealer said all service was done. What is the reason for this? And is there anything else I should look at, its stock.
Thank You
Bryan

Your plunger may be faulty,or it may be your mass air flow sensor.