This 2012 VW Tiguan 2.0 TDi had a P0121 code "throttle position sensor implausible signal" when I checked using VCDS. The engine management light was not illuminated but I'm pretty sure it would have been soon.


In this video I show the thick carbon deposits on the throttle valve that turned out to be the cause of the problem. You'll see the valve after cleaning with Wynn's diesel EGR extreme cleaner.


After cleaning and refitting, I deleted the code and test drove the vehicle. The code didn't come back and there were huge improvements in throttle response and fuel economy. Well worth doing!


Links:
Wynn's diesel EGR extreme cleaner https://amzn.to/3067FS8
New seal for the throttle valve https://ebay.us/JwiWae
Blog post to go along with this video https://andrewfixes.com/p0121-vw-tigu...


#Tiguan #diesel #P0121 #VW #volkswagen