I don’t see that as causing an O2 sensor fault. If the O2 sensor is mounted as it was in the 2.1L Vanagons it is susceptible to being fouled from road spray. In addition they sometimes have difficulty staying hot enough to work properly. From VW there was a clip on shield that tried to help with both of those issues.

Dennis
 

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Neil N
Sent: Saturday, March 5, 2016 3:08 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Fuel injector cleaner: harm O2 sensor?

I added STP or similar injector cleaner to fuel tank. 1/2 bottle per 1/2 tank then remainder in a full tank. The stuff smelled mostly like diesel fuel if I recall.
No run issue prior, figured it was good maintenance to run injector cleaner through.  Check engine light coming on recently while driving was something that used to happen but that was due to a missing "sensor ground" ECU 33 if I recall. (yes)

http://www.a2resource.com/electrical/management/motronicvr6aba.html

I connected that missing ground over a year ago, which solved that issue, so was surprised to see the MIL come on while driving. Wondered if any WBX users had run into an O2 fouling situation after using injector cleaner in fuel tank

When light came on this time, it threw a 2324 DTC for O2 system:

http://www.a2resource.com/electrical/codes/motronic.html

Neil.

Neil.

On Sat, Mar 5, 2016 at 8:08 AM, Dennis Haynes <d23haynes57@hotmail.com>
wrote:

> What type of cleaner? Was this running a bottle through the fuel tank 
> or one of those run the engine  on the injector cleaner kits? Usually 
> I find that using fuel and oil additives including cleaners or even 
> change of brands and types is part of a response to something going 
> wrong or at least changing and then when the inevitable happens it 
> will be the fault of that product.
>
> Dennis
>
>