When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I have a 2010 Q7 TDI 70,000 mile and had to have mine replaced. Cost me $937 all in after a $75 "coupon" the dealership gave me. I spoke with another mechanic who works on diesels and he would have charged me slightly less but not much more.
I fixed my NOx Sensor.
I have a 2012 Q7 TDI. My CEL light came on around 52k miles. I had just had the car in for it's 50k service. The dealer told me I needed a new NOx sensor. I believe the error code was P2200. I was quoted around $900 to replace it. I contacted AoA and they would not consider covering it under warranty. I told them this seems to be a common failure since there are postings all over the web. And the fact that the part seems to go through multiple revisions per year as indicated by the letter changes at the end of the part number. They denied that it's a common failure. It's also not covered under any emissions warranties.
After researching it online, I saw that the sensor was easy to get to so I decided to try cleaning it.
The control unit is located next to the power steering reservoir and the cable runs next to the upper fuel filter which leads to the sensor. The part number on the back of mine is 059907807 E. The letter at the end represents what version you have. The lower the letter, the older the version.
I removed the complete sensor assembly, cleaned the sensor tip with brake cleaner, then let it soak in seafoam over night. The next day, I again sprayed brake cleaner into the small holes on the tip of the sensor. I reinstalled the sensor. The CEL light did not go off immediately. After I drove about 20 miles, the CEL light turned off and has stayed off.
If you try this, do not try unplugging the sensor from the control unit. You must unplug the smaller connection that plugs into the small square control box. I also suggest coating the sensor thread with a small amount of anti seize when reinstalling it.
This makes me wonder how many of these are bad vs simply clogged. It stinks that the dealer makes no attempt to clean these vs charging ~$1,000 to replace it.
Rumrunner-
Good for you! A lot of parts including O2 sensors and fuel:air mass flow sensors eventually get oil contamination that "kills" them, and at shop labor rates no one wants to gamble that an hour or two in a solvent wash might clean them.
FWIW, do note that SeaFoam, according to their own MSDS, is a mixture of naphtha (fuel stock), very light petroleum oil, and "IPA" which is better known as "isopropyl alcohol".
In other words, a little alcohol to blow things off cylinder walls, a little more light oil to immediately relubricate the cylinder walls, and some fuel stock to make sure it keeps running, and is diluted properly.
For cleaning sensors, I'd just suggest that plain isopropanol (sold in 74-90% solutions for $1/qt in drug chains) would be a good way to soak things, followed by the brake cleaner to really clean off everything. Brake cleaner is 50-state legal usually as Stoddard fluid (dry cleaning fluid) or something similar, and still available as carbon tetrachloride (toxic concerns but effective) outside of Cali. Often same can is "red" for the carbon tet and "green" for the safer stuff, fwiw.
Our other car had a TPS warning light on last week, dealer said there was one wheel with a dead battery, time to change all four for $250. I said thinks, we'll ignore the light, it has never really been more reliable than my old-fashioned "look at the tires". I'm so happy that Audi doesn't use batteries for that! Even if our system still isn't terribly precise.(G)
You can get your nox sensor at this site. Audi genuine parts catalog online
Through October 31st take an additional 10% off using coupon code TENOFF. For example, nox sensor 059-907-807-H is $367.50 before the discount.
Last edited by oemaudiparts; 10-08-2015 at 03:07 PM.
We have had two bad NoX sensors replaced at our dealership since the fix last November. Both were no charge. They always give loaner cars.Last time I got an A8. Our car has 56k On it. They always wash & vacuum as well
09-09-2015, 07:19 AM
