After my engine would warm up approx 2 min, the air/fuel would show the engine leaning out. If you turn the car off then restart after 5 seconds it would start rich, as normal, the go to normal operation. Sometimes you may have to do this twice. I changed the O2 sensor with a Bosch universial. Now it runs rich until you get 2500-3000 @ 55+ then it runs in the normal range amber/green on the air/fuel. I have been told that OEM is the only sensor to use, that universal sensors are not accurate. I removed a Denso sensor.
94 JDM GSR
JR supercharger
Thanks.