Question about 1991 GMC Sierra

Open Question


Posted by Anonymous on


6 Suggested Answers


6ya staff

  • 2 Answers


Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017



  • 196 Answers

SOURCE: need to know where sensor 1 (oxygen sensor) on bank 1 is located

It would be on the left header pipe as you sit in the truck. Its the sensor in front of the cat

Posted on Jan 17, 2009



  • 1986 Answers

SOURCE: where are the oxygen sensors located?

There will be one located before, and one located after the catalytic converter for each exhaust that you have

Posted on Sep 10, 2009


  • 432 Answers

SOURCE: i have a 2002 gmc sierra 1500, need to change the

There are several located within the exhaust system(PIPE)You need to know witch one.

Posted on Jan 12, 2010


  • 203 Answers

SOURCE: where is the oxygen sensor

there should be 2,both are in the exhaust 1 behind the cat.converter & 1 upstream
if the truck has dual exhaust it may have more than the 2.if your reading codes it will
list them as bank 1 sensor 1 or 2. sensor 1= upstream 2 = behind cat
good luck

Posted on Jun 13, 2011


Ryan Arbuckle

  • 44 Answers

SOURCE: I would like to know

From my research, there are multiple O2 sensors on the exhaust system. They can be found near the catalytic converter, before and after it. O2 sensors are easy to find by the wires sticking out of the exhaust system and the mounting bungs for them.

Posted on Jul 22, 2011

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

3 Answers

Where is the oxygen sensor located on a 454 Chevy pickup engine

Anrez, your 1991 Chevy trucks O2 sensor could be located in the Y pipe just ahead of converter or in the front portion of the converter.
Check the attached links,instruction and guides, Good luck
"I hope this helped you out, if so let me know by pressing the helpful button. Check out some of my other posts if you need more tips and info."
How to change Oxygen Sensor 1995 Chevy Suburban
How to o2 sensor replacement Chevy Silverado GMC Sierra 88 95 Tahoe Yukon...

Jul 21, 2016 | Cars & Trucks

1 Answer

Were is the oxygen sensor on a GMC box truck?

Google search engine model, type and the words oxygen sensor location. The search results will provide you with both images and links to locate it on your engine.

May 01, 2015 | GMC Cars & Trucks

1 Answer

Where are the oxygen sensors located on a 2006 gmc envoy

We have 2 locations, upstream before the CAT, and dowstream below the CAT. The upstream is on the passenger side at the exaust manifold very easy to access from the top. The downstream one is after the cat, accessible from underneath. The connector for this one is a PIA, up near the top of the tranny. But doable if you're in the right position.

Jan 11, 2014 | 2006 GMC Envoy

1 Answer

Oxygen cam sensor on 2007 gmc canyon location

I've never heard of an oxygen cam sensor

Mar 13, 2013 | GMC Canyon Cars & Trucks

3 Answers

Where is the oxygen sensor located on a 92 gmc 2500

Your oxygen sensor is located between your exhaust manifold and the cad. It is a little sensor that screws into the exhaust pipe itself. There will be a wire on it which plugs into a small clip. When you see it you will know it. It is the only thing that screws right into the exhaust. I hope this helps you out.

Aug 25, 2011 | 1992 GMC G2500

1 Answer

A friend of mine hooked up a computer to My 1992 gmc sierra pickup and got error codes 44 and 43. But is not sure what they are. Please help

43= electronic spark control- ESC module is not receiving a knck signal from knock sensor.
44=Lean exhaust. check wiring and connectors from oxygen sensor to the ECM.

Aug 14, 2010 | GMC C1500 Cars & Trucks

1 Answer

I just bought a used engine for my 1988 lincoln and its reading history codes of 91, 41, and 34. What are these codes

91 (engine running) heated oxygen sensor indicates system lean, left side
91 ( cont. memory) no heated oxygen sensor switching indicated, left side.
41 (engine running) lean right side.
41(cont. memory) no heated oxygen sensor switch,right side.
34 egr valve pressure transducer/position sensor sonic voltage above closed limit.
(tech. manual Haynes #59010)

Sep 25, 2009 | 1998 Lincoln Town Car

1 Answer

Oxygen sensor

Hello gobabygo1, my name is JShreader. Thank you for choosing

There is 4 Oxygen Sensors on this model Truck. I uploaded a picture showing you exactly where each of the 4 Oxygen Sensors are located. It is in .pdf format. You can download it by clicking HERE. I hope this helps you. If you have any more questions or need any more diagrams, please don't hesitate to ask...Thanks again, JShreader!

Mar 31, 2009 | 2003 GMC Sierra 1500

1 Answer

Location of oxygen sensor

The only thing that comes out of the exhaust with a wire coming from it, is the oxygen senser. It is right behind the manafold.

Dec 22, 2008 | 1986 Dodge W150

2 Answers

Check Engine light flickers occasionally

Check the oxygen sensor or catalytic converter might be bad; but I would check the oxygen sensor first. Also clean the cold air intake sensor, if there is something cover it then you'll see the checkengine flickers on but your engine is running fine.

Aug 23, 2008 | 1991 Toyota Pickup

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

427 people viewed this question

Ask a Question

Usually answered in minutes!

Top GMC Experts


Level 3 Expert

85206 Answers

Jonah Oneal

Level 3 Expert

14092 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22484 Answers

Are you a GMC Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides