1996 Tahoe O2 sensor question

My apologies if this has been asked / answered:
I need to replace my O2 sensor at Bank 1 Sensor 1 and Bank 1 sensor 2. Can someone tell me where these are located...? Thank you.

Welcome to AF.
Bank one is always on the no 1 piston side. Odd no pistons.
Bank 2 sensor is on even piston no. side.
Bank 1 sensor 2 will be between the cat and and bank 1 sensor 1

What codes no are you getting?
What engine and mileage?
Remember code does not say replace sensor but to check it out.
Several other thing besides a bad sensor can set a 02 sensor code.
If you need help on it post back your code no.
MT

Thank you for replying so quickly...!!! My 96 Tahoe (V8, 5.7L) has 170,00 mi. on it. I'm receiving codes P0141, P0305 and P0135. I plan on changing the plugs and wires to help cure P0305. I was hoping to at least get a starting point in looking for the O2 sensors. Thanks again.

135 and 141 are 02 sensor heater circuit codes.
Always check for power to the heater circuit fuse and power to and ground at 02 sensor and plug in.
Also do the tune up and clear codes and see what it does or if any codes come back.
Engine not running right can affect 02 sensor operation and set 02 sensor codes.
Good luck and let us know how it does.
MT

Thanks again. I was changing the plugs / wires and looking for leaky hoses, etc. when something broke. A hose with anti-freeze attached to some metal coming from the top of the engine. I took pics but we're not allowed to include attachments. ANY help would be much appreciated...!!!

Thanks again. I was changing the plugs / wires and looking for leaky hoses, etc. when something broke. A hose with anti-freeze attached to some metal coming from the top of the engine. I took pics but we're not allowed to include attachments. ANY help would be much appreciated...!!!

A picture needs uploaded to the web page and then a link to it posted.
Is it is threaded into intake and is it broke at the threads going into the intake and is it made out of pot metal?
If so they make replacements.
But I would go the Dealer OEM gm replacement part.
If the threaded part on a pot metal one is broke it is a bear to get out of intake.
Snap on and some good tool places make a special extractor for it.
If you need more help post back and up load a picture if you can.
MT

Thanks. Yes, the threaded part did break off into the intake. I've been trying to upload the pics, but I keep geeting "page cannot be displayed" after it says "my picture is being processed." I'll try again later. Meanwhile I'll see if I can get an extraction tool for this thing. Thanks again, MT...!!!

Here is a how to on picture posting link.
http://www.automotiveforums.com/vbulletin/showthread.php?t=498376

Thanks. I tried looking for an extraction bit or tool to back this metal out of the intake. Here are some pics of the mess. Any advise is much appreciated, as always.
http://i200.photobucket.com/albums/aa191/amack_23/extraction2-1.jpg (http://i200.photobucket.com/albums/aa191/amack_23/extraction2-1.jpg)
http://i200.photobucket.com/albums/aa191/amack_23/extraction.jpg (http://i200.photobucket.com/albums/aa191/amack_23/extraction.jpg)
http://i200.photobucket.com/albums/aa191/amack_23/extraction2.jpg (http://i200.photobucket.com/albums/aa191/amack_23/extraction2.jpg)

From the pictures it looks like the old pot metal fitting.
Good news is it is up front where you can get to it good.
Bad news is a extractor will no usually remove the broken off part.
But if you can find one try it.

The way I get them out is to take a kack saw blade or power hack saw and slice it almost into the threads about 5 places around the inside of it and then start chipping it out a little piece at a time.
The pot metal will crumble up and chips out easy.
After it is all chipped out run a pipe thread tap into the hole and straighten up threads.
Good luck
MT

Thanks for all your help again, MT. That metal easily crumbled as you expected. Now, I'm off to changing my O2 sensors. I'll post back if I get stuck. Thanks again...!

Thanks for all your help again, MT. That metal easily crumbled as you expected. Now, I'm off to changing my O2 sensors. I'll post back if I get stuck. Thanks again...!

You are welcome.
Glad you got it out ok. Some of them can be a pain.