I was getting the code for the right bank, upstream O2 sensor. I figured I'd just change all three. I went to Autozone to buy the Bosch O2 sensors. They had a 'universal' for ~$70 and an 'O.E.' for ~ $80. I spent the extra money for the O.E. They told me all three were the same. Well, when I got into it, I noticed the downstream O2 sensor did not look like the two upstream sensors. From the look/shape of the actual sensor to the plug connection. I went back today and their computer still shows all three as being the same. Anyone else experience this? What should I do? Try another autopart store? Does anyone know the Bosch part number for the downstream sensor? Should I go to a dealer? Would the 'universal' work? Thanks so much.

 

The downstream O2 sensor that is after the cat converter is a heated 4 wire O2 sensor the two upstream Y-pipe bank sensors are 3 wire sensors. Also each O2 sensor is of a different wire length
so they should have three different product numbers.

When we replaced O2 sensors on my friends Y-pipe they had three different part numbers at the Autozone we went too.

IMO I would just change the failed sensor and leave the other two alone to save some cash.

 

Thanks. What do you mean 3 different part numbers? There should only be two. The two upstreams and the one dowsnstream. Do you know the Bosch part number for the downstream O2 sensor?

 

The wire lengths and plastic pop-in connector positions are different for the two upstream O2 sensors. If you were to remove both upstream sensors and look at them side by side they are different, the sensor for the rear bank is longer and has more plastic pop-in clips than the front bank sensor does. There are 3 different parts numbers last time I checked at Autozone, but I dont have them off the top of my head.

 

That's odd. I used the same part number for the two upstream sensors and everything worked out fine.

 

Anyone else know about the Bosch part numbers? I think I will just have to order from Courtesy - but it was a lot more so it would be nice to be able to get the Bosch locally. $103 each at Courtesy vs. $80 at Autozone. Thanks.