2017 Duramax 6.6 L5P Nox Sensor Replacement

Replacing the rear nox sensor on a 2017 chevy silverado 2500 6.6 l5p duramax turbo diesel.

[@motakabon6778]

I wish I see how you position yourself undeath the truck to get to that sensor not enough room to get your arms around that area. You make it look so easy! Great video!

[@brandonalexander1831]

I’ve had p20ee and p249d codes come up on my 17 l5p. A couple of people said it was the nox sensor bad on the downstream side. I have replaced the one upstream on the turbo. Any help would be appreciated. Thank you

[@drewsshoplife]

It could be a failed nox sensor, there are so many parts that have to work together in that system it could be an issue in the def delivery side. The easiest way to check is with a scan tool and drive the truck at freeway speeds for 10-20 minutes and make sure the nox sensors are working. The front sensor should read higher than the rear, also under deceleration at higher speed they both should get to zero or very close. Make sure you are using gm parts and reset the nox sensor after replacement.

[@adamabarquez8257]

How do you reset the nox sensor. I replaced the nox b because i had p20ee code Now im getting p22a7 and u029e

[@adamabarquez8257]

So, do I need a snap on scan tool, I have a banks idash but I don't think I have those functions on it

[@brianscott3762]

What size is that socket for removal?

[@drewsshoplife]

Its a standard oxygen sensor size 22mm.

[@70lsswap]

Mine nox 2 sensor is reading negative numbers when press the throttle all the way to -100 is the tell you it’s bad

[@drewsshoplife]

Not sure on the exact way your checking it. But what I like to do is drive it for 8-10 miles and check the readings. Sometimes the rear nox sensor takes a very long time to warm up and start working. Ideally you want it to read high when accelerating and after a few seconds of deceleration at 50-70mph it should go to zero.

[@70lsswap]

On my snap on freeeway speeds warmed up when I press on the throttle reads negative numbers all the way to -100

[@drewsshoplife]

@@70lsswap are you having any codes or warning messages?

[@70lsswap]

Yep P22FE nox 2 performance

[@youchris67]

You don't always have to replace the Nox sensor; just clean it. Removing it is best to clean it. Once removed, soak it in fuel injector cleaner for 4-6 hours. Then use carb and choke cleaner and be sure the straw sprays into all the holes. Reattach the Nox sensor, then reset the on-board ECM by disconnecting the battery for two-minutes and then reconnect the battery. The "Check Engine" light should no longer be lighting up. An even easier way to clean the Nox sensor--especially if it is stuck--is to simply clean it while it's still on the vehicle. I got my "Check Engine" light to go out by cleaning it while still screwed into the exhaust system by simply removing the break master cylinder vacuum hose, inserted the straw from a can of throttle body and carb cleaner into the vacuum hose and reattach it with the straw still connected. Next, start the engine and slowly and patiently spray the cleaner into the vacuum hose until half, or even the entire can has been consumed. The engine may sputter a few times but release the spray button to allow the fuel-air mixture to come back to normal. After this procedure is completed, remove the empty can from the vacuum hose, make sure to firmly reconnect the vacuum hose, turn off the engine, and disconnect and then reconnect the battery just like above. Once the ignition is turned back on, the "Check Engine" light should now be off. Worked for me and is still working.

[@drewsshoplife]

What kind of truck did you try this on? Please don’t spray anything down your intake on a diesel engine , depending on the chemical it can cause a runaway condition and permanent engine damage. This may have worked on a gasoline engine and it is possible to clean a nox or oxygen sensor , if this nox sensor malfunctions and sends my customers truck into limp mode while towing a trailer in the middle of the desert , they would be more than happy to replace the sensor than spend thousands on towing it back to me. Also unhooking the battery rarely works anymore, these computers can hold memory for days at minimum to prevent people from bypass emission faults (I’ve tested this theory).

[@youchris67]

Thanks for the info. Very helpful and very good disclaimer. However, it worked perfectly! For me it did and saved me $785.00 potential rip off dollars. Oh, I am aware of runaway diesels! Terrifying, but spectacular! to see! Anyway, I took the risk; however, I am not giving out the names of the brands to prevent harm to their intellectual properties. I am therefore, not going to name which brand(s) of cleaner(s) that I used, but I followed the careful directions observed and I continued on, because I was pissed at the cost to fix it when in debt and the fact that the damn thing is seized in with risk of a rounded off hex bolt face--so I decided to research "techniques," and this one seemed "PLAUSIBLE," as the "Myth Busters" would always say, but "We don't recommend that you try it!". Use that approach; however it worked magnificently! I think it also cleaned gunk on the intake and flapper, as well as other down flow sensors, because my truck is running better and has wheel chirping acceleration now! Therefore, for me, the risk was worth the results. Also, I sprayed the throttle body and carb cleaner in with very short spurts and listened for change in idle RPM. What I found was that spraying too much started choking off the engine--with RPM dropping, not rising, but when very little was sprayed in--there was no engine acceleration. Everything worked out fine and my ECU was able to digest (literally) the info instantly to reset that brief rough idle. I only performed short bursts at a time until I had eventually used the entire can. One week and 300-work commute miles later, and my Colorado is running better than ever, and is even faster than ever! Turn off traction control and I can make this little 2.8 Duramax peal out! I did it this past weekend. Anyway, I got the results that I wanted and my ECM is again receiving Nox data from a perfectly functioning Tier #1 Nox sensor that that rip-off crook nearly bilked me out of my hard earned money for. Karma is social media! Now, we can do crap ourselves and be able to feed ourselves and our dependents by exposing these rip-off scum mechanics.Worst than lawyers. Anyhow, I not only saved $780.00 minus the $11.99 for the spray, but I also saved $1300.00 by performing my own break job, front and rear, for only $175.00! I simply got replacement OEM break pads and installed them myself. I did not replace my rotors because they do not have to be replaced since they are not warped, grooved, or gouged. Break shops no longer lathe, "turn" rotors--they will only replace them. If your rotors do not cause your steering wheel to shimmy while breaking--especially when decelerating down from high speeds, but instead, if the rotors still demonstrate good breaking performance and good breaking feel, with the only problem having been the "squeakers," before replacing the original worn break pads--then stop (literally and figuratively) with new pads only and then save yourself some money and do research and just just do it! However, use good judgement and do it safely. I wore safety glasses and I had my ABC fire extinguisher nearby. Again--it worked well and all is well for me and my beloved diesel pickup truck! @@drewsshoplife

[@danielmeisterics8391]

What year is your truck

[@youchris67]

@@danielmeisterics8391 2017 and still running like new.

[@Ruffles206]

Thanks guys for the tip, today 3/22/24 in my 2023 diesel 2500, I got my engine light on and I check with my banks power derringer to check the codes and I saw this code P24DA I look in google and say is the bank 1 sensor I’m guessing is the one from the turbo so I’m going to do a deep clean like you mentioned, but what was funny my truck have little over 10k miles 😅 I’ll keep posted for you guys

[@user-pd4di2te3e]

what was the code you talk too much