Honda Car Forum

Hello All,

I've tried searching all over the internet to find the answer to these questions and I think the best way is to just ask it in a forum like this.

I have a 2003 Honda Accord EX V6 about a month ago my orange engine light came on. I checked the gas cap and when I refueled it went off after a couple days. It's been coming on for a few days and going off every since. I took it to an auto parts store and they read the computer for me and gave me the print out. I've been trying to figure out what the part is that I need to get it fixed but I'm having a hard time figuring it all out. It says it's the Air/Fuel Ratio Sensor but I was wondering:

Is the Air-Fuel Ratio Sensor the same as the Oxygen Sensor?

Here's what the readout says exactly:

Troubleshooting P2631
OEM Brand: Honda

Definition:
AF sensor label circuit high voltage - 21

Probable Causes
1. Open or short circuit condition
2. Poor electrical connection
3. Failed AF sensor 21

It appears that it would be sensor 21 but I don't know how to go about finding that particular part considering that I really don't know what the part is exactly.

Any help is very much appreciated! Thanks so much!

My 2002 service manual shows the A/F sensor to be the same thing as the primary O2 sensor or the first one in the exhaust flow. The secondary is the one in the cat.

I will check into that a little more. If that's all I would have to get then you may have just made my day! Just so I'm not mistaken is that the Owner's Manual or a Repair Manual... or something completely different? Also this may seem silly (keep in mind that I pretty much know nothing about cars) but the O2 sensor is one of the oxygen sensors, correct?

O2 sensor is oxygen sensor. It is an air/fuel ratio controller in that it modifies the duration of fuel injection. I do not show that code in my service manual (actually 2 manuals - one for the car and one for the V6 differences). These books cost about $100 for the two, but I find them to be worth it. All it takes is one saved trip to any service station to pay for itself. I don't think this sensor is a very expensive part but I don't know about labor. Sometimes exhaust stuff is hard to deal with because the heat and moisture in exhaust tends to corrode everything. Not to mention the location can be hard to get to.