SunPilot
New member
I recently had a check engine light come on. It read a code for the oxygen sensor behind the Cat. I did some research and realized that often this code is thrown because the upstream sensor (a/F sensor) is faulty, giving bad readings. So, I decided to replace both sensors on the driver's side (bank 1).
The O-2 sensor under the truck was a piece of cake, but the a/f sensor was not so easy. I am doing this write-up for that upstream (bank 1 sensor 1) in case anyone needs to do this job. Hopefully some of my tips will be helpful to someone. Note: this is on a 2007 V-8 engine.
The first thing I did was remove the front wheel. My truck is lifted and I don't have the rubber mud guards in place between the frame and fender, so I could easily see the A/F sensor hiding on top of the exhaust pipe right behind the manifold.
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/36251724901/in/photostream/" title="20170802_120840"><img src="https://farm5.staticflickr.com/4362/36251724901_0908d5a939_b.jpg" width="576" height="1024" alt="20170802_120840"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/35580662263/in/dateposted-public/" title="20170805_084527"><img src="https://farm5.staticflickr.com/4426/35580662263_b94d5956c0_b.jpg" width="1024" height="576" alt="20170805_084527"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
I tried to get my hand in there to no avail. A wrench certainly wasn't fitting. I decided to take the steering coupler off to gain more access.
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/35992223560" title="20170803_104935"><img src="https://farm5.staticflickr.com/4369/35992223560_69be94f080_b.jpg" width="1024" height="576" alt="20170803_104935"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
The coupler merely slides up and down on splines and connects the steering wheel to the steering box. Be sure to scribe some marks on the coupler and the upper and lower splines before removing...this will index the steering wheel back to it's original position. After marking the coupler and splines, just remove the two bolts, and then slide the coupler up. This will free the bottom rod, then slide the coupler back down and it will come right off the upper rod, leaving a lot more access space for your hand and tools.
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/35552793294/in/photostream/" title="Steering Coupler"><img src="https://farm5.staticflickr.com/4422/35552793294_8713a92733_b.jpg" width="576" height="1024" alt="Steering Coupler"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/36388218045/in/photostream/" title="20170805_085025"><img src="https://farm5.staticflickr.com/4385/36388218045_346fe019d0_b.jpg" width="576" height="1024" alt="20170805_085025"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/35552790264/in/photostream/" title="20170805_085030"><img src="https://farm5.staticflickr.com/4414/35552790264_3ebe8509d8_b.jpg" width="576" height="1024" alt="20170805_085030"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
Now, the fun begins. The connector is way up behind the engine and almost impossible to release. My hands are too big to get back there, and even if I could get a hand in there, there wasn't room for the other hand to pull the connector apart.
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/36220436072/in/photostream/" title="20170805_084614_001"><img src="https://farm5.staticflickr.com/4336/36220436072_b2588fc079_b.jpg" width="576" height="1024" alt="20170805_084614_001"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script> My solution was as follows:
I used a piece of "tie wire" like what they use on construction sites to tie rebar together. (I always keep a roll of this wire in my garage because it has so many uses.) I looped the tie wire around the wire pigtail of the sensor and left enough sticking out into the wheel well so I could pull on it. Then I used a tool I had lying around with a bend on the end, to push the connector tab down. A long allen wrench would also work. I pushed the tab with the bent tool and gave a tug on the tie wire. Voila, it was an easy task to separate the connector!
Bent Tool
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/36220440562/in/photostream/" title="20170802_123609"><img src="https://farm5.staticflickr.com/4406/36220440562_dee94d6235_b.jpg" width="576" height="1024" alt="20170802_123609"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
Tie wire
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/36388213485/in/photostream/" title="20170805_085354"><img src="https://farm5.staticflickr.com/4425/36388213485_f17ac5b7c2_b.jpg" width="1024" height="576" alt="20170805_085354"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
Tie wire looped around the sensor pigtail
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/35991808070/in/photostream/" title="20170802_123514"><img src="https://farm5.staticflickr.com/4357/35991808070_7f43beec86_b.jpg" width="1024" height="576" alt="20170802_123514"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
After the connectors were separated I used a box wrench to loosen the sensor. I tried a 22mm wrench first, but it didn't have enough angle at the box end to slide over the sensor. I found a 7/8" wrench in my tool box (almost the same size as 22mm). It had a little more angle and was enough to slide down over the sensor. With the steering coupler removed, I had enough room to break the sensor loose. I took the wrench off and finished removing the sensor with my hand. (Be careful if your engine is not cooled down...that manifold can get mighty hot)
The old sensor and the new sensor
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/36220428332/in/photostream/" title="20170805_091408"><img src="https://farm5.staticflickr.com/4359/36220428332_c968f07819_b.jpg" width="576" height="1024" alt="20170805_091408"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
The installation was a piece of cake. I threaded the sensor (be sure to coat the threads with anti-seize) into the bung on the pipe and screwed it in with my hand. Then I used the wrench to tighten it. I was able to reach my hand in and push the pigtails together. Then, simply slide the steering coupler back up the upper rod splines (make sure your index marks line up), then positioned the lower rod under the coupler and slid the coupler back down (again aligning the index marks) until it seated.
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/35580281873/in/photostream/" title="20170805_093130"><img src="https://farm5.staticflickr.com/4418/35580281873_a8631f0d0e_b.jpg" width="576" height="1024" alt="20170805_093130"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
Then replace the two bolts, torque to 27 ft# and replace the wheel. Job done.
I spent some time thinking of how to access the A/F sensor, so it took me awhile. Once I had the procedure figured out, it was not a bad job, and probably took about 45 minutes start to finish.
The O-2 sensor under the truck was a piece of cake, but the a/f sensor was not so easy. I am doing this write-up for that upstream (bank 1 sensor 1) in case anyone needs to do this job. Hopefully some of my tips will be helpful to someone. Note: this is on a 2007 V-8 engine.
The first thing I did was remove the front wheel. My truck is lifted and I don't have the rubber mud guards in place between the frame and fender, so I could easily see the A/F sensor hiding on top of the exhaust pipe right behind the manifold.
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/36251724901/in/photostream/" title="20170802_120840"><img src="https://farm5.staticflickr.com/4362/36251724901_0908d5a939_b.jpg" width="576" height="1024" alt="20170802_120840"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/35580662263/in/dateposted-public/" title="20170805_084527"><img src="https://farm5.staticflickr.com/4426/35580662263_b94d5956c0_b.jpg" width="1024" height="576" alt="20170805_084527"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
I tried to get my hand in there to no avail. A wrench certainly wasn't fitting. I decided to take the steering coupler off to gain more access.
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/35992223560" title="20170803_104935"><img src="https://farm5.staticflickr.com/4369/35992223560_69be94f080_b.jpg" width="1024" height="576" alt="20170803_104935"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
The coupler merely slides up and down on splines and connects the steering wheel to the steering box. Be sure to scribe some marks on the coupler and the upper and lower splines before removing...this will index the steering wheel back to it's original position. After marking the coupler and splines, just remove the two bolts, and then slide the coupler up. This will free the bottom rod, then slide the coupler back down and it will come right off the upper rod, leaving a lot more access space for your hand and tools.
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/35552793294/in/photostream/" title="Steering Coupler"><img src="https://farm5.staticflickr.com/4422/35552793294_8713a92733_b.jpg" width="576" height="1024" alt="Steering Coupler"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/36388218045/in/photostream/" title="20170805_085025"><img src="https://farm5.staticflickr.com/4385/36388218045_346fe019d0_b.jpg" width="576" height="1024" alt="20170805_085025"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/35552790264/in/photostream/" title="20170805_085030"><img src="https://farm5.staticflickr.com/4414/35552790264_3ebe8509d8_b.jpg" width="576" height="1024" alt="20170805_085030"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
Now, the fun begins. The connector is way up behind the engine and almost impossible to release. My hands are too big to get back there, and even if I could get a hand in there, there wasn't room for the other hand to pull the connector apart.
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/36220436072/in/photostream/" title="20170805_084614_001"><img src="https://farm5.staticflickr.com/4336/36220436072_b2588fc079_b.jpg" width="576" height="1024" alt="20170805_084614_001"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script> My solution was as follows:
I used a piece of "tie wire" like what they use on construction sites to tie rebar together. (I always keep a roll of this wire in my garage because it has so many uses.) I looped the tie wire around the wire pigtail of the sensor and left enough sticking out into the wheel well so I could pull on it. Then I used a tool I had lying around with a bend on the end, to push the connector tab down. A long allen wrench would also work. I pushed the tab with the bent tool and gave a tug on the tie wire. Voila, it was an easy task to separate the connector!
Bent Tool
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/36220440562/in/photostream/" title="20170802_123609"><img src="https://farm5.staticflickr.com/4406/36220440562_dee94d6235_b.jpg" width="576" height="1024" alt="20170802_123609"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
Tie wire
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/36388213485/in/photostream/" title="20170805_085354"><img src="https://farm5.staticflickr.com/4425/36388213485_f17ac5b7c2_b.jpg" width="1024" height="576" alt="20170805_085354"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
Tie wire looped around the sensor pigtail
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/35991808070/in/photostream/" title="20170802_123514"><img src="https://farm5.staticflickr.com/4357/35991808070_7f43beec86_b.jpg" width="1024" height="576" alt="20170802_123514"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
After the connectors were separated I used a box wrench to loosen the sensor. I tried a 22mm wrench first, but it didn't have enough angle at the box end to slide over the sensor. I found a 7/8" wrench in my tool box (almost the same size as 22mm). It had a little more angle and was enough to slide down over the sensor. With the steering coupler removed, I had enough room to break the sensor loose. I took the wrench off and finished removing the sensor with my hand. (Be careful if your engine is not cooled down...that manifold can get mighty hot)
The old sensor and the new sensor
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/36220428332/in/photostream/" title="20170805_091408"><img src="https://farm5.staticflickr.com/4359/36220428332_c968f07819_b.jpg" width="576" height="1024" alt="20170805_091408"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
The installation was a piece of cake. I threaded the sensor (be sure to coat the threads with anti-seize) into the bung on the pipe and screwed it in with my hand. Then I used the wrench to tighten it. I was able to reach my hand in and push the pigtails together. Then, simply slide the steering coupler back up the upper rod splines (make sure your index marks line up), then positioned the lower rod under the coupler and slid the coupler back down (again aligning the index marks) until it seated.
<a data-flickr-embed="true" href="https://www.flickr.com/photos/132372278@N04/35580281873/in/photostream/" title="20170805_093130"><img src="https://farm5.staticflickr.com/4418/35580281873_a8631f0d0e_b.jpg" width="576" height="1024" alt="20170805_093130"></a><script async src="//embedr.flickr.com/assets/client-code.js" charset="utf-8"></script>
Then replace the two bolts, torque to 27 ft# and replace the wheel. Job done.
I spent some time thinking of how to access the A/F sensor, so it took me awhile. Once I had the procedure figured out, it was not a bad job, and probably took about 45 minutes start to finish.
