We have 2 accords in the family one is a 99 the other a 02.
They are both throwing codes for the 02 sensor.
Honda has 2 different part #s for the cars. Aftermarket companys have the same part #s for both cars. The sensor from the dealer for the 99 is $130.00 and the sensor for the 02 is $230.00.The aftermarket sensors are 83.00 each.
Question:
How can the aftermarket sensors be the same? Has anyone had any good/bad luck witht the aftermarkets?
I am planning on ordering the sensors from honda, But I wouldn't mind saving $150.00 buyin the aftermarket sensors. Any help would be appreciated.

It's not uncommon for aftermarket o2 sensors to cover a lot of applications...they all work the same, with minor differences in design at the business end...

I wonder why you have codes on both...most will run 150,000 miles or more and never see an o2 sensor fault...is it the upstream or downstrem that are coding?

It is the upstream on both. The 99 has had the engine light on for quite a while I have just neglected it. And the other just came on. The 99 has around 130,000 and the 02 has about 80,000. I ended up ordering both from honda. I didn't want to take a chance with the aftermarket and roast a converter.
I was more curious about the things I hear about the aftermarkets only lasting 10,000 miles and tossing a light again. Anything on that?

the big diff between the 2 is the aftermarket is usually "universal" meaning you need to wire it in... whereas the honda one will come with the plug you need and it will plug right in

It's very difficult to find aftertermarket A/F sensors. You have to make sure that the sensor is for ULEV or SULEV engine. I was doing a research for a month on two on finding cheap A/F sensors. I ended up buying the OE A/F sensor for $130 on ebay with matching OEM part number.

Don't get mixed up with regular Accord Oxygen sensor, they look exactly the same but with shorter wires.

If you can find the aftermarket one, it usually doesn't come with harness, you'll have to cut it and connect them together (if you are lucky it might come with an intructions, but most doesn't.) If you also have one of the wires flopped, the sensor will go bad and you have to buy a new one again... I don't think it's worth it.

I know it's lame to pay more for A/F sensor than regular O2 sensor... but we need it to pass smog!

Here is links for the cheapest sensor I could find.

A/F for 98-00 Accord 4cyl ULEV F23a4 engine
http://cgi.ebay.com/ebaymotors/98-00-Honda-Accord-DENSO-Oxygen-Air-Fuel-Ratio-Sensor_W0QQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1 247QQcategoryZ33557QQihZ001QQitemZ110225558775QQrd Z1QQsspagenameZWD1V

I couldn't find 02 Accord sensor at the moment, but the same seller was selling it. You can call them up. They sell it for the same price.

I bought sensor from them and I got it within few days. Very good seller.

Good luck!