Hi,
I have a 2001 accord EX, it has a F23A4 engine (F23A4-4522080), a few weeks ago, check engine light is on, and I got code P1166 and P1167, I did following try to fix the issue:

1. I checked every fuses in fuse box of both driver and passenger sides, all of them are good
2. I checked 40amp power seat fuse in under hood fuse box, it is also good (one post says this might be the cause)
3. I replaced upstream O2 sensor with this Keenso sensor:
after I replaced sensor, P1166 is gone, but check engine light is still on with P1167, the car runs kind sluggish, both before and after new sensor, but no other issue

I wonder what else could I do?

and I am in California, not sure if this matters since I saw some posts says somehow "car sold in California" is a bit different

 

The A4 needs a proper denso A/F sensor. The cheap aftermarket sensors are usually a bust.

https://www.hondaautomotiveparts.com...9tYXRpYw%3D%3D

Honda, 36531-PAA-305 or Denso, 234-9014

dont get fooled and buy a knock off part, a real denso sensor is approx 120.00