I have been looking around on forums to see what the cause of the code P0171 (1 of 2) - System Too Lean (Bank 1), might be and from what most people say, it is the Front O2 Sensor that has to be replaced. If this is the case, can someone tell me where the front O2 sensor is located on this model (2005 Honda Accord Hybrid V6) and if there are 2 front O2 sensors or just 1. If there are 2 front O2 sensors, should I replace both. Also do I need any special tools to replace this sensor?

Any and all help is appreciated.

Thanks in advance!!

 

The front O2 sensors are on the top of the exhaust manifolds (#9 & #10). But I'm not sure which one is "bank 1" - I've only had 4-cyl cars. If there's something (label, sticker?) which indicates the cylinder numbers (1 thru 6) it's the side that contains #1.



It's not real profound but there IS a special socket for that, to allow the wire to go through. With age & heat it's probably too tight for an open-end wrench.

 

Thanks for the information! I will take a look around the compartment tonight once the engine cools down. Fingers Crossed