So I have a 92 civic si and I was having troubles with my car it was running sluggish and what not code 41 would pull up swapped the O2 sensor but code would not go away. Finally a buddy of mine suggested to swap my ecu with his, same ecu that goes in mine (p28) but his is in a del sol, his car runs great no problems no CEL. Swapped it car runs 100 times better but it's still throwing code 41 looked at the sensor looks good and wires. Any ideas?

 

O2 heater fuse.

 

if a ecu fixed the cel, pop the cover and look for bad capacitors \ resistors on yours.

the original ecu is 27 years old at this point the electronics don't last forever

 

The CEL is still on but it the CEL doesn't come on in my buddies car with the same ECU