This is my first post on here about my car. I have a 2007 Audi A4 and it has 102,500 miles and my check engine light came on 4 weeks ago. The OBD showed it being the fuel pressure sensor at first so I got it fixed. The light came on again and this time the OBD showed the fuel pressure regulator being the issue so I got it fixed along with the fuel filter. I also replaced the spark plugs. The light came on again, but I am out of ideas and so is my mechanic. Please help if anyone has any good recommendations.
Just found a website, which shows that it could be the oxygen sensor, loose or faulty gas cap, catalytic converter, mass airflow sensor, and spark plugs with wires. Well, I changed the plugs, but didn't change the wires. If any of these listed above, wouldn't it have set off the OBD Scanner to give me a code?