Oxygen Sensor--have I been ripped off?
 

I have a '96 4runner limited. Several mos ago a light came on on the dash. Turns out it was an O2 sensor (autozone verified after they used their gadget). So I went on-line and noted there's 2 sensors--one forward of and one behind the catalytic converter. The rear one I figured must be the culprit since it was basically falling off its mount due to corrosion. So I removed it & did not replace it. There was a hole left in the exhaust pipe which I patched with some aluminum and a c-clamp--which worked great--squelched the noise. I also disconnected the battery cables and put them back on. This made the problem light go off, but unfortunatley not for long.

So fast forwarding to present day...I just took the car in to a garage due to my emissions sticker expiring. I did not pass the test of course due to the light being on. I came back a week later to have a new O2 sensor replaced. So I drive the car home and sure enough, the light comes back on. So I look under the 4runner and there is still no rear sensor there--no new one, nothing--just as I'd had it for 5 mos. And no new front one put in either--I obviously know where they go since i'd removed the rear one months ago.

So I was just charged $250 for removing and replacing an O2 sensor. I just called the guy and he swears he did replace and in fact has the part! We'll sort it out on saturday. Is there more than 2 sensors on this vehicle? I was thinking I was totally ripped off and the guy would blame it on a subordiante but he is saying he has the old part from my car and will show me on saturday---very confusing. My guess was he just disconnected the electric, making the light go off and was hoping it just wouldn't come back on. But again, he's saying he has the part off my car!

At a minimum he should have noticed there was no rear sensor there at all, but he made no mention of it. So, are there more sensors on this 4runner that I'm not aware of? If there are they are in hard to reach places---seems at a minimum he did not pursue the path of least resistence. Also, an ebay photo of the part number on the invoice looks like the two sensors I am familiar with.

thoughts? comments?

There are only two. You got ripped off. Go here to find your sensors http://www.urdusa.com/index.php?cPath=9_13

Then go to Amazon.com to buy them.

Buying both of them and installing yourself will be less than $250