I have a 2005 model that is idling rough most of the time but occasionally runs fine. Seems to be using a lot of gas but it is new to me so I am not sure. The awd is inoperative also. Any ideas or suggestions? Thanks

 

Start by clearing the codes and seeing which ones come back first. Do you know how old the spark plugs are? I would pull, inspect and replace them with the proper parts if unknown. If you have a compression gauge - that would be the time to use it. Is the car at stage 0? PCV system and all vacuum lines working properly? No air leaks, either vacuum or pressure (from the turbo to the intake manifoled)?

The awd - Scan the awd control unit - It's the DEM (differential electronic module) If your scan tool won't talk to that module you can try some tests - xemodex has some on this page -

https://xemodex.com/us/diagnostic-flow-charts/

 

Thanks. I will work my way through the list. It is stock. No mods and it has 367000 miles on it. Engine is strong, not using any oil that I can tell but I have not been driving it very long.

 

I cleared all the codes and the MAF code keeps returning. I found a collapsed tube on the evaporative emission control system so I am thinking that one of these little gray canisters my be blocked. Could this be throwing the MAF code?

 

Turn the AC off it goes away. Turn it back on it runs rough and lopes. Showing misfire on 3 &5. Newish spark plugs and coils. Runs great at driving speed and hard Acceleration is great.