Hello fellow subaru owners, I recently got a 2001 Legacy GT for both my first subaru and my first car, it has been running great and I'm beyond happy with my purchase but last night while driving home on the freeway, my check engine light came on, everywhere I have looked said to check the fuel filler cap and/or blame it on an emissions control unit malfunction.  How would you guys recommend I diagnose the issue without breaking the bank?  Thank you all.

Emissions codes can pop up for the simplest and silliest of things. Including a fuel cap that isn't tightened all the way.

 

Most of the auto parts chains will pull the check engine codes for free. Stop by an Auto Zone, Advanced Auto parts, O'reillys etc. And have them pull the code. Write down the code and research the possible causes of that specific code. Very often it will be a vacuum hose leak somewhere, or simple sensors that are no longer functioning properly.

 

Check engine lights are rarely a sign that there is a large issue. Certain things can be ignored for years and some things make more sense to replace to help the engine operate as it should.

 

Welcome to the board! When you get a chance, post up a picture of your car. My sister and brother in law recently bought a 2000 Legacy GT as their first car and LOVE it.