When I was driving to work yesterday, the check engine light came on my 2005 Acura TL. Car has approx. 174k miles. Received the following 2 codes from the Autozone diagnostics:

P2138 - APP Sensor A/B incorrect voltage
P0108 - MAP sensor circuit voltage high

Would anyone which sensor to replace first? APP sensor was replaced by the dealer about 3 years ago when I had the CEL, VSA lights on and the car went on a limp mode. So not sure if APP sensor is again the culprit.

 

reset CEL by unhooking battery cables for a minute or two...should clear the codes...
now if the code(s) come back, you'll have a better idea of which one. (the APP code may have been stored on the computer..., by resetting the codes, you'll get a more realistic idea of which one you'll need to replace...if both codes come back, then both items are failing and you could further test them via multimeter )

 

You might consider the MAP sensor this time around. From what I understand, the MAP sensor going out can inadvertently affect the APP sensor.