I have a 2005 Touareg 4.2L with around 124k miles that has been throwing me the P0431 code. A local mechanic has cleared the CIL a few times, tested the O2 sensors which seemed fine. He ran across a TSB that may relate to my vehicle that involves a software update via VAGCOM at a VW dealer. He spoke with them over the phone and they claimed there was no software update for this vehicle. His concern is if he replaces the cats, the issue may still persist. Mechanic recommended I take it into the VW dealer (3-4 hours away) anyway for a second opinion with their diagnostics before I drop the bills for new cats. He's still optimistic about a software update.
The last two times the CIL came on I noticed a very slight sluggishness at slower speeds when very gently accelerating. My assumption is if it is a software update as my mechanic hopes, the change in performance wouldnt be noticed.
This is also based on the assumption that the software update changes the threshold for the O2 sensors so they are not so sensitive to trip the codes.
Part of me wants to just change the cats. I dread a 3-4 hour drive just to hear I need new cats..
The last two times the CIL came on I noticed a very slight sluggishness at slower speeds when very gently accelerating. My assumption is if it is a software update as my mechanic hopes, the change in performance wouldnt be noticed.
This is also based on the assumption that the software update changes the threshold for the O2 sensors so they are not so sensitive to trip the codes.
Part of me wants to just change the cats. I dread a 3-4 hour drive just to hear I need new cats..