Preface: car is a 1996 Civic DX hatchback with an H22A4 swap running Hondata S300 V1 in a P28 ecu with a Phearable.net basemap and running with closed loop disabled (no o2 sensor, open loop)

The last time I drove the car it gave me issues with bogging while coasting and initial acceleration (less than 30% throttle position)... i had this problem when I first got the car, replaced the ecu with the S300 and it went away

Now it has a constant code 41 (o2 sensor) code even if I have it running open loop... how can this be? Is something wrong with the board? I opened it up and didn't see any indication of burnt chips or anything. Any help is appreciated.

 

Code 1 is for O2 sensor signal. Code 41 is for O2 sensor heater. Disable the heater as well... selecting Open Loop is only one part of the equation.

 

H22 basemaps run like garbage. I've tuned hundreds of them, and the basemaps never run right. You NEED to fully tune it.
I digress, there's a possibility either your S300 is bad, the ECU isn't chipped right, or your calibration is corrupted.
- Start with a new calibration (make sure your software and firmware are updated).
- Try the S300 in a known-working ECU, make sure datalogging is operating correctly.
- Check the Hondata website and make sure your S300 is not counterfeit.
- Try a different S300 (or ostrich with a double-female header) in your ECU and verify operation.