Downstream o2 sensor

My check engine light has been on for about six months now. I’ve gotten the first two oxygen sensors replaced as well as a catalytic converter. My body shop tells me that I need to replace the downstream oxygen sensor (the one after the CAT?) and they are charging me $400 for parts and labor. Is this something I can go without replacing? If not, is there a cheaper way to go, such as buying the part myself?

FYI this is for a 1998 Toyota Camry 4 cyllinder

It’s not easy changing the downstream O2 sensor in this vehicle. First you need to access the plug for the sensor which is located under the carpet below the drivers seat. Then you push the plug/wire with the rubber bushing through the hole in the floor. Then you need an O2 sensor tool to remove the old sensor and install the new sensor.


how much should a repair like this cost? is 400 a decent price?

correction: this is a 1998 toyota camry v6

And, you want to change the rear oxygen sensor because someone tested it and found something specific wrong with it?

You will need a special socket for your ratchet. You can buy it at the auto parts store. It will have an open side so that you can loosen and tighten the Oxygen sensors in spite of their wires. You won’t save much though. Most of the $400 quote is for the part.

Autozone used to sell universal Oxygen sensors (for $80 each), but they didn’t have a plug on the end. If they still sell them, and you are willing to splice with wires, you might consider them, but I can’t attest that they will work.

If it is a V6, there might be two downstream Oxygen sensors. If that is the case, $400 is reasonable.

If you only have one downstream Oxygen sensor, you should look into doing this yourself. It isn’t that hard if you have the right tool (see below).