Why wont my Mazda 626 rev past 3000 rpm?

If your Mazda 626 won't rev past 3000 RPM, it could be due to several issues. Common causes include a clogged fuel filter, a malfunctioning throttle position sensor, or problems with the ignition system. Additionally, it might be in "limp mode" due to a detected fault, limiting engine performance for safety reasons. Checking for error codes with an OBD-II scanner can help diagnose the problem more accurately.