Engine light is always on on my CRV Honda 2002 4 CYL. We got a reading on scan tools of p1166 and P1167. My mechanic turned off via same tool, light disappear but soon after turning the engine on, the engine light came on and stayed on... 2 questions:
1. what p1166 and 67 stand for and
2. Why Engine light stays on even though we reset the ECM?
Thanks for the Help
Mike

P1166--Primary HO2S (No. 1) Heater System Electrical
P1167--Primary HO2S (No. 1) Heater System

Replace the Oxygen Sensor; then, erase both codes. After that, the CEL should not come back on.

Here's how to replace the Oxygen Sensor yourself:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563.html#post223376

Go with a Denso Oxygen Sensor.