Your emission issue is causing the SH-AWD light to come on from time to time.
You need to take your vehicle to the dealer because they have more sophisticated engine scanners that will provide more specific sub-codes that can pinpoint exactly what and where the problem is. Without a more specific sub-code information, you will be guessing and replacing potentially healthy components.
Maybe some other higher end specialized Acura vehicle shops may have scanners that can provide that information, too..
I've been really frustrated with the MDX, for some reason the Emission light keeps coming on and off. Originally it started coming on and went away when I filled the gas all the way up and tightened the gas cap by 5-6 clicks. The strange thing is the other day the emission light came back on again and now it's been 5 days and the emission light is still on. Once in a while the SH-AWD light will come on with the Emission as well but if I turn the car off and back on then SH-AWD error code will go away but the Emission one is still there. Can someone please help me?
2011 Pearl White MDX Advanced
... OEM towing, 20 mm wheel adapters,
... rails/crossbars, black wheel well trims,
... side windows acrylic deflectors,
... Michelin Latitude Diamaris HP 285/45R19,
... Full size spare tire,
... 6000 Kelvin HID's
2010 Acura TL Tech.
2001 Mercedes ML 320
2005 Mercedes ML 500 AMG Package