Re: 2003 CR-V code P1166 (sauer04)
Your oxygen sensor is going bad.
You need to replace it. Total out the door at a dealerships is over 400 bucks (parts and labor) parts alone will cost you about 250. It's a ceramic type o2 sensor, and if you're thinking about going with bosch, it'll fail in about 80 miles. Bosch itself isn't a terrible brand, but on the crv's it's really finnicky. NGK/NTK are your best bets for replacements.
#24410 for the rear and #24666 for the front. I'd venture to say the primary is bad, but it could very well just be a connection problem, so start there first.