2004 Mazda RX8

Engine Performance problem
2004 Mazda RX8 Two Wheel Drive Manual

I have a 2004 RX8 rotary 1.4L It runs very rich almost enough to make your eyes water. The only code is low efficency on cat. I have had it checked out and was told the cat is not bad. Any ideas? I have been running super in it for 3 months it also gets poor gas milage even driving it gently. Please any help would be welcomed. Thank you.
Rob Quaglia
March 22, 2010.

Probable causes of an engine running rich are as follows: 1. Fuel pressure not within specs. Can be cause by restricted fuel return line or defective fuel pressure regulator.
2. Defective Oxygen Sensors.
3. Leaking injectors.
4. Coolant temperature sensor out of calibration.
5. Restricted air intake system.

Mar 22, 2010.