I went to replace my oxygen sensor today on my 97 Riv and couldn't do it! Where the exhaust header connects to the exhaust pipe is a huge lip and the oxygen sensor is so close to this you can't get a freakin wrench around it! I wanna shoot the engineer that did this! argh. anyway, I guess I'll have to rent an o2 sensor socket. also, I had disoconnected the wireharness and forgot to hook it back up because I couldn't change it and drove the car.. the SES light did NOT come on. What is up with that?

I had the same problem. I could get the boxed end on it, but I didn't have enough room to turn it after I got the wrench on. The O2 socket got it right out.
I don't have an answer for the light though.

maybe the computer didnt have enough time to realize a problem

Mine was a PITA to change but I was able to finally get down there and change it with a regular wrench.

I tried to do mine with a wrench once..... live and learn. I had the car up on jacks and tried from underneath, paasenger side, drivers side, damn near sitting on the engine and I still couldn't even get it to nudge. So I went out and spent $10 on the right socket, and then it came off like it was only on finger tight. I couldn't get any leverage on it with a wrench no matter how I went after it. I suggest the socket, worth the money.

It was hard for me to get leverage too. Did you try starting the car for a few seconds to warm it up a bit? I finally did that and it came right off with a wrench, piece of cake. Go figure

sorry to say this but mine was easy...i had the car up on ramps and just got under it and twisted!!!

It'll probably cost the same to buy the socket as rent one. Will come off real easy with the socket. Crowfoot wrench also works.

The O2 sensor light won't come on until the computer senses the coolant is warm enough & PCM starts expecting variable voltage from the sensor but doesn't see the variation it expects. Look at SES light as you lift off the gas after accelerating or just cresting a hill at freeway speeds.

Does SES come on with key ON but engine NOT running? If not, bulb may be bad. Otherwise you have problem with wiring, coolant sensor (PCM one not guage), or the PCM.

Yeah the o2 is a baffleing thing to get off with a cresent wrench...I Being 6'5 and with long arms couldnt even get a good angle at the damn thing... But I got the socket and my 3 hrs sweating with a wrench *my car was hot* Well it sucked to say the least. Just go buy the socket and if you dont have the xtra money just take it back.

This, I discovered, is how Auto Zone does their "free tool rentals" in the first place. You put down a "deposit" of whatever the purchase price is, then return the tool within four days or thereabouts and get a full refund. This was how they explained it to me the other day when I went in looking to borrow a MacPherson strut spring compressor.