Hi All !

I have 2002 Hyundai Sonata (Model GLS V-6) with only 25k miles , whose "check engine" light keeps coming on (always before my NYS inspection is due) the past 3-4 years.

It first occurred after a replaced the battery, then seemed to have gone away. I also used the grease around the gas cap trick before and it only temporarily solved it.

There are no mechanical problems ( that I know of) and engine runs fine. Since I enjoy doing a lot of my work / regular maintenance, I'm pretty good at making sure all fluids are tapped off and changed regularly.

I just had the computer checked at Auto Zone and came up with the following OEM CODes: P1134 (O2 Sensor) and P1154 (Heated O2 Sensor).

They told me that the Sonata takes (4) Four O2 Sensors, 2 in the front (upstream) and 2 in back (downstream).

The P1134 Code (is Bank 1, Sensor 1) and P1154 Code (is Bank 2, Sensor 1). Can anyone tell me to which these Sensors (locations) these codes refer too ?

I suspect Front / Upstream but am not sure. I would hate to replace all 4 at same time if not needed.

Other than checking the O2 Sensors (cleaning or replacing) are there any other parts I should Check ( EGR Valve, etc ) ??

Thanks.

 

This pic should help:



Bank 1 is the bank of cylinders on the firewall side
Bank 2 is the bank of cylinders on the radiator side

Sensor 1 is the O2 sensor before the cat
Sensor 2 is the O2 sensor after the cat

So the two you want to change are the sensors before the cat on both sides of the engine.

 

Thanks

 

Tried using your diagram, but: there are 2 between the front manifold and radiator and another 2 toward the back, not to mention the others below (before & after the catalytic converter. I am now counting up to 8 (originally told only 4), all similar in size and type.

Can anyone tell me (or send me a specific link) for the exact locations for each as I am now confused on which ones to replace and don't want to be taking them all apart.

Also, my Haynes Manual was of little help.

 

There are only 4. Please go to a trained mechanic.