My car seems to be having fuel pressure or flow issue. So I began some basic diagnoses last night. While the car is at idle the afr is right around 14.7. With a static fuel pressure of 50 psi. If I turn up the pressure slightly to 55-60 psi the afr leans out to 16-17. While I lower the pressure to 45psi the afr does the same which makes sense.

My question is why would the engine lean out if the fuel pressure is increased?

Any thoughts are appreciated

 

doesnt make sense at all... weird. Try disconnecting your o2 sensor and doing the test again.