2002 Sonata P1154 code

It's a problem with your bank 2 upstream oxygen sensor. First, call the dealer back with your vin and have them check to see if there are any recalls on the vehicle. There was a recall to reprogram the pcm which addresses this issue. If this hasn't been done, they should be happy to do it free of charge. If it has already been done and you're beyond the warranty period, the repairs are your monkey.

Hyundai has had some problems with these oxygen sensors and has made some attempts to fix the problem. Although they originally appeared to be working, I still see many failures of this oxygen sensor.

If you'd like to try this job yourself, it's the oxygen sensor in the front manifold near the top. The part number for the sensor is

39210-3916A, but be aware that the distribution of this sensor is currently being restricted by Hyundai because they don't have enough to fill all the orders. I actually checked into the availability of this part a few days ago and it appears plenty should be available in about a month.

Thanks for the info.

I went to an online auto store to ask about the part and they said to double check the info you gave. They stated that the "bank 2" is the rear oxygen sensor and, therefore, would not be the "upstream". Can you clarify that?

Also, is the item I need the one listed on this web page:

Thanks, John

hyundaitech,

Another question popped up while looking for this item.

Would this be the sensor located before the catalyst or after the catalyst?

Thanks, John

Bank two refers to which bank of the engine the sensor is in. On your car, bank two is the one by the radiator and bank one is the one by the firewall.

Upstream means it's before the catalytic converter.

The application information on the chart on your link is incorrect. Hyundai made a change in oxygen sensors for this engine in 2003 but the chart does not indicate that. I'm guessing that the chart is correct for the earlier model years but not the later model years. The descriptions list a right bank but not a left bank. You'll need the left bank (bank 2, or front bank) precatalyst sensor (sensor 1, or upstream sensor).

Hyundaitech,

Thanks again for the info.

I've located a Bosch replacement for this sensor which will be here today.

I looked for the sensor but did not readily locate it. Do I have to remove the manifold cover to get to this part?

No. You will probably need a special oxygen sensor socket (it has a slot up the side for the wire to come out), a long extension, and at least one universal joint.

You can service this one from the top. Some people remove the radiator fan to increase access. It screws into the manifold on the passenger side and the wire comes out around the a/c piping.