I just left Toyota and they are telling me I need to replace my oxygen sensors and want to charge me $525 for it. I would to replace them myself but I do not know where they are located. Can anyone tell me where they are located so I can see if I can figure this thing out myself. I found them both, one for $75~ and the other for $125~ . Pictures would be nice or some steps

 

I have never replaced oxygen sensors on an xD but it should be fairly universal. You are going to have one sensor before the catalytic converter and it will be mounted probably some where in the manifold (this is the expensive one BTW). This is the sensor the computer uses to help determine the proper fuel/air mixture. Next will be a sensor after the converter and this sensor is for emission purposes only. They are easy to find since all you need to look for is some wires running to the exhaust system. Find the proper size wrench to remove the sensor and replace with the new model.

 

i replace the lower one on my downpipe before, I have a tc, I don't think there are much different between xd and tc.
If the dealership want you to replace them, i assume your xd have the check engine light on. If not, you shouldn't need to replace it. If u go to Auto Zone or Advance Auto Parts, They can read the code for you and tell you which O2 sensor need to be replace.
I order my sensor from TRDSPARK.com They were very helpful over the phone.

 

Great, thank you for the info I did not know autozone would be able to tell which sensor could be the bad one. Yes the check engine light came on and I was able to find some photos on here of someone taking out they're o2 sensors, hopefully they are in similiar locations.

 

yeah, they do it for free. Advance auto parts scanned my code and told me it is my lower o2 sensor cause the problem.
i found out my home made anti fouler for the o2 sensor rusted off the car. so my sensor was dangling by the wire.

Now days, they let me scan it myself. they just need to hold my driver's licnese.

 

how many miles on your ride? This should be covered by the emissions warranty.. the dealer might be ripping u off.. they are actually with that price they quoted.
Get a O2 sensor socket to remove and install it.. makes it easy and you wont break it in the process. Also use anti-sieze on the threads.. be sure not to contaminate the tip of the sensor with it, if you end up doing it yourself..

 

Some of the aftermarket O2 sensors are a bit clunky. Instead of just the sensor with a wire that plugs in, they may have a converter box that you have to wire in. I'd rather pay a little more for a plug-and-play sensor. As mentioned, you'll need to have the code(s) read to see which sensor is bad. You can (as mentioned) have Autozone do it for free, or you can buy yourself a $60 code reader and always have it on hand. Most dealerships charge $80 to read your codes. I have a $120 code reader that also displays lots of info, like coolant temperature, intake air temp, MAF readings, etc. It also has "plain English" display instead of just giving you a code number. If you buy one, make sure it is CAN or CAN-bus compatible -- that's the new standard for engine computers.

I have this one: http://www.amazon.com/Equus-3130-Dia.../dp/B000KID31K

 

I'm planning on buy a sensor from advance auto parts because I have coupons =)
What brand should I buy from them?

as well as, spark plugs.

 

I need to replace the O2 Sensors.
Do I go with NGK or Denso?

Thank you.