Okay.....p2175 is low air flow/restriction detected (slow accumulation). I was already thinking that this was going to be the code. I have personally seen this code numerous times and each time the cost was a simple repair. The throttle body and throttle plate being dirty is the primary reason for this code. Cleaning it is the repair. This can easily be performed with an old tooth brush and a can of throttle body cleaned. With the engien off, take the air cleaner and housing off the engine so as to gain access to the throttle body. Then using your fingers.....hold the throttle plagte open by pushing on top or bottom of the throttle plate ( which one escapes me at the momnet, most likey the top). This will open the plate and then hold it open while spraying a few shots of throttle body cleaner and then scrub with the old tooth brush. Repeat this until clean. Then reinstall all the components and then its time to start it. It will be somewhat difficult to get started at first so use the throttle and keep it runnning until all the cleaner is burnt off. Then if the check engine light is on, you can disconnect the battery cables and hold them together for about 2 minutes then reconnect them. This will clear any codes and reset all the modules at the same time.
As mentioned this is a code I have seen numerous times and I have also found other dealers over look it. Most of the time they dont research it enough to find the cause.
Simple problem....simple solution.
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