I have a 2002 Subaru Legacy with 181,000 miles. The transmission is a rebuild, and the car is not accelerating. When the A/C is running, the car will stall while idling. It also blows air even when the fan is not actively on. The 'Check Engine' light is on and flashing. I want to get an idea of what I am looking at before I take it to a mechanic and drop thousands of dollars on a diagnosis, as I am on a very tight budget.
Thank you for writing in. The lack of power is more likely caused by an issue with the engine rather than the transmission based on the fact running the AC makes it worse. However, it is impossible to tell if it is fuel or spark related, or if there is another issue going on without doing some further testing. The first thing you can do is have the check engine light scanned, in order to tell you what issue has been detected. This can be done for free at most local automotive parts stores. However, a proper diagnosis is the only way to be sure. Good luck!