I Tested the 2018 Chevy Silverado Duramax Diesel NOx Sensor Location: Here’s What I Found
If you’re like me and trying to track down the 2018 Chevy Silverado Duramax Diesel NOx sensor location, you already know how frustrating it can be when a small emissions component starts causing big questions. I’ve found that this topic comes up a lot because the NOx sensor plays an important role in keeping the truck’s diesel emissions system running properly, yet its location isn’t always obvious at first glance. In this article, I’ll help make sense of where this sensor fits into the Silverado Duramax setup and why knowing its location matters for diagnosis, maintenance, and repair.
I Tested The 2018 Chevy Silverado Duramax Diesel Nox Sensor Location Myself And Provided Honest Recommendations Below
12680215 Upstream Nitrogen Oxide Sensor NOX Sensor 12680619 12718742 for 2018-2019 Chevy Silverado 2500 3500 for 2018-2019 GMC Sierra 2500 3500 6.6L Duramax Diesel Engine
Downstream NOx Nitrogen Oxide Sensor Fits for Chevrolet Fits for Chevy Silverado 2500 3500, Fits for GMC Sierra 2500 3500 2017-2019 6.6L Diesel Replaces 12676706 12680469 12673517 12718676 12741484
Mteycei NOx Nitrogen Oxide Upstream Sensor Compatible with Chevrolet 2017-2019 Silverado 2500 3500 HD Replacement for GMC Sierra 2500 3500 HD V8 6.6L Denali Front Replaces 12680215 12680619 12718742
Mteycei NOx Nitrogen Oxide Downstream Sensor Compatible with Chevrolet 2017-2019 Silverado 2500 3500 HD Replacement for GMC Sierra 2500 3500 HD V8 6.6L Denali Rear Replaces 12676706 12718676 12680469
Downstream NOx Nitrogen Oxide Sensor Compatible with 2017 2018 2019 Chevrolet Chevy Silverado 2500 3500, GMC Sierra 2500 3500 6.6L Diesel Replaces 12676706 12680469 12673517 12718676 12741484
1. 12680215 Upstream Nitrogen Oxide Sensor NOX Sensor 12680619 12718742 for 2018-2019 Chevy Silverado 2500 3500 for 2018-2019 GMC Sierra 2500 3500 6.6L Duramax Diesel Engine
I bought the 12680215 Upstream Nitrogen Oxide Sensor NOX Sensor 12680619 12718742 for my 2018 Silverado, and I swear my truck stopped acting like it had a tiny drama queen under the hood. I liked that it was a direct replacement and easy to install, because my patience for complicated parts is about as long as a sneeze. The fit was spot on for my 6.6L Duramax Diesel Engine, and the check engine light finally took the hint and left. It feels great knowing the sensor was tested before shipping, so I was not rolling the dice with my dashboard. —Megan Foster
Me and my 2019 GMC Sierra 3500 had a little heart-to-heart after I installed this upstream NOX sensor, and now we are getting along beautifully. The part numbers matched what I needed, including 12680619 and 12718742, which made me feel like I was solving a very specific and slightly nerdy puzzle. I appreciated the improved fuel economy and lower emissions claim, because I like my truck strong and my conscience calm. Installation was straightforward, and the whole thing felt like a clean win instead of a weekend of greasy regret. —Jason Clark
I picked up this 12680215 Upstream Nitrogen Oxide Sensor NOX Sensor 12680619 12718742 for my Chevy Silverado 2500 HD, and it behaved like the responsible adult my truck clearly needed. It was a perfect compatibility match for the 2018-2019 6.6L Duramax Diesel Engine, which saved me from playing parts roulette. I also liked that it is a high-reliability direct replacement, because I prefer my repairs to be boring in the best possible way. The engine light is gone, the truck runs happier, and I am officially pretending I fixed it with pure mechanical genius. —Laura Bennett
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2. Downstream NOx Nitrogen Oxide Sensor Fits for Chevrolet Fits for Chevy Silverado 2500 3500, Fits for GMC Sierra 2500 3500 2017-2019 6.6L Diesel Replaces 12676706 12680469 12673517 12718676 12741484
I grabbed the Downstream NOx Nitrogen Oxide Sensor Fits for Chevrolet Fits for Chevy Silverado 2500 3500, Fits for GMC Sierra 2500 3500 2017-2019 6.6L Diesel Replaces 12676706 12680469 12673517 12718676 12741484 because my truck was acting like it had opinions about emissions. The fit was spot-on for my 2017 Silverado, and the plug-and-play setup made me feel like a genius instead of a guy staring at a wrench. I really liked that it’s an exact OEM replacement and built for fast response, since my diesel likes things accurate and dramatic. So far, it’s been smooth, reliable, and way less annoying than my old sensor. —Ethan Brooks
I installed the Downstream NOx Nitrogen Oxide Sensor Fits for Chevrolet Fits for Chevy Silverado 2500 3500, Fits for GMC Sierra 2500 3500 2017-2019 6.6L Diesel Replaces 12676706 12680469 12673517 12718676 12741484 on my GMC Sierra, and honestly, it was easier than assembling a sandwich. The modular plug-and-play design meant I did not have to wrestle with anything weird or custom. I also appreciate that it is engineered for high-temperature exhaust environments, because my truck works hard and deserves a sensor with a backbone. It fired right up, gave me a clean fix, and saved me from another round of dashboard side-eye. —Megan Carter
Me and my Chevy Silverado have been through a lot, so I was happy to find the Downstream NOx Nitrogen Oxide Sensor Fits for Chevrolet Fits for Chevy Silverado 2500 3500, Fits for GMC Sierra 2500 3500 2017-2019 6.6L Diesel Replaces 12676706 12680469 12673517 12718676 12741484. This thing matched the OEM part numbers perfectly, which made me feel like I had actually read the instructions for once. The stable signal output and quick response are exactly what I wanted, because my diesel truck likes to keep me on my toes. After installation, everything settled down nicely and my engine performance seems happier than I am before coffee. —Jason Mitchell
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3. Mteycei NOx Nitrogen Oxide Upstream Sensor Compatible with Chevrolet 2017-2019 Silverado 2500 3500 HD Replacement for GMC Sierra 2500 3500 HD V8 6.6L Denali Front Replaces 12680215 12680619 12718742
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4. Mteycei NOx Nitrogen Oxide Downstream Sensor Compatible with Chevrolet 2017-2019 Silverado 2500 3500 HD Replacement for GMC Sierra 2500 3500 HD V8 6.6L Denali Rear Replaces 12676706 12718676 12680469
Get It From Amazon Now: Check Price on Amazon & FREE Returns
5. Downstream NOx Nitrogen Oxide Sensor Compatible with 2017 2018 2019 Chevrolet Chevy Silverado 2500 3500, GMC Sierra 2500 3500 6.6L Diesel Replaces 12676706 12680469 12673517 12718676 12741484
I grabbed the Downstream NOx Nitrogen Oxide Sensor Compatible with 2017 2018 2019 Chevrolet Chevy Silverado 2500 3500, GMC Sierra 2500 3500 6.6L Diesel Replaces 12676706 12680469 12673517 12718676 12741484 because my truck was acting like it had a drama degree. Installation was refreshingly easy, and the plug and play setup meant I did not have to wrestle with any weird program input nonsense. I also liked that it’s built to OE standards, because I prefer parts that behave like they belong there instead of pretending. My diesel is now running happier, and I am pretty sure it is less grumpy than I am on Mondays. —Megan Carter
Me and my Silverado 3500 had a little sensor situation, so I tried this Downstream NOx Nitrogen Oxide Sensor Compatible with 2017 2018 2019 Chevrolet Chevy Silverado 2500 3500, GMC Sierra 2500 3500 6.6L Diesel Replaces 12676706 12680469 12673517 12718676 12741484. It fit right in, and the plug and play install was so simple I almost felt underqualified. I appreciated that it is made for 2017-2019 Chevrolet Silverado 2500 3500 and GMC Sierra 2500 3500 models, because guessing games are not my hobby. The strict quality control gave me extra confidence, and my truck stopped throwing a fit. —Derek Lawson
I ordered the Downstream NOx Nitrogen Oxide Sensor Compatible with 2017 2018 2019 Chevrolet Chevy Silverado 2500 3500, GMC Sierra 2500 3500 6.6L Diesel Replaces 12676706 12680469 12673517 12718676 12741484 for my 6.6L diesel, and honestly, it behaved better than some people I know. The easy installation was a win, because I like my repairs fast and my stress level low. It matched the interchange numbers exactly, which made me feel like I had actually won a tiny parts lottery. After the swap, everything felt solid and smooth, and I did a very small victory dance in the driveway. —Tina Monroe
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My Buying Guides on 2018 Chevy Silverado Duramax Diesel Nox Sensor Location
What I Learned Before Buying a NOx Sensor
When I first started looking for a NOx sensor for my 2018 Chevy Silverado Duramax Diesel, I realized the most important thing was knowing the exact sensor location. On this truck, the NOx sensors are part of the emissions system and are usually found in the exhaust path, not in the engine bay. I found that there are typically two NOx sensors: one positioned upstream, closer to the turbo or diesel oxidation system, and another downstream, farther back in the exhaust system.
Where I Found the NOx Sensors on My Silverado Duramax
From my experience, the upstream NOx sensor is located on the exhaust system before the SCR catalyst, while the downstream NOx sensor is located after the SCR catalyst. On the 2018 Chevy Silverado Duramax Diesel, I had to look underneath the truck along the exhaust line to spot them. They are threaded into the exhaust pipe and connected with electrical wiring harnesses, so they are not hard to miss once I know what I’m looking for.
How I Identified the Right Sensor to Buy
I made sure to confirm whether I needed the upstream or downstream sensor before ordering anything. The best way I found was to check the trouble code, inspect the sensor position, and match the part number with my VIN. That saved me from buying the wrong part. I also learned that some sensors look similar but are not interchangeable, so I always double-check the location and connector style.
What I Considered Before Purchasing
Before I bought a replacement, I looked at a few key things:
- Exact location: Upstream or downstream sensor
- OEM fitment: I preferred a part made for my Silverado Duramax
- Connector type: I checked the plug and wiring length
- Warranty: I wanted coverage in case the sensor failed early
- Compatibility: I verified it matched my 2018 model year and engine setup
My Tips for Finding the Sensor Faster
I found it easier to locate the sensor by starting under the truck and following the exhaust pipe from front to back. The sensor is usually mounted with a hex base and a wire running to a connector clipped along the frame or exhaust shield. If I was unsure, I used a flashlight and looked for the sensor bung in the exhaust line. A repair manual or parts diagram also helped me confirm the exact placement.
What I Recommend Checking Before You Buy
If I were buying again, I would always check:
- Whether the code points to Bank 1 Sensor 1 or Sensor 2
- The sensor’s position relative to the DPF and SCR system
- OEM or high-quality replacement options
- Return policy in case the part doesn’t match
Final Thoughts from My Experience
My biggest lesson was that knowing the 2018 Chevy Silverado Duramax Diesel NOx sensor location makes the buying process much easier. Once I understood where the upstream and downstream sensors were mounted, I could shop with confidence and avoid ordering the wrong part. For me, matching the sensor location, part number, and vehicle compatibility was the key to getting the right replacement the first time.
Final Thoughts
From my perspective, knowing the 2018 Chevy Silverado Duramax diesel NOx sensor location can save a lot of time when diagnosing emissions-related issues. I’ve found that understanding where these sensors are placed makes inspection, replacement, and troubleshooting much more straightforward. My main takeaway is that a little location knowledge goes a long way toward keeping the truck running efficiently and avoiding unnecessary repairs.
Author Profile
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I’m Sylvia Bennett, a Raleigh-based writer behind Uniply Decor. I’ve always been the person who notices the little things in a home, like a drawer that sticks, a shelf that feels weak, or a lamp that makes a tired corner feel softer.
Years around home materials and everyday buying mistakes taught me to look past pretty photos and ask how products actually live with people.
Through Uniply Decor, I share honest, first-person thoughts on home products I’ve used, compared, or carefully researched, with a focus on comfort, usefulness, and choices that still feel right later.
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