What causes a fuel injected motor to run extremely rich?

Answer 1

I had the same question, so I asked my father-in-law who owns a shop. He suggested first changing the air filter, then moving to the oxygen sensor, even though the check engine light is not on. He also said to check the thermostat, if it is not closing than the sysstem is not closing which will cause the engine to think it's cold, therefore the engine willrun fastetr trying to warm up. If you take your car to an Auto Zone, Checker, or other auto supply house, they can put it on their scanner which will show any hidden codes. Good luck, I hope this helps