The day after I bought my A6 the check engine light came on about an hour after I drove it off the lot. Right after I drove it off the lot, I put in some fuel injector fluid (that I bought from a BP station) and fueled the car up.

The next day I took it to the auction house and the mechanic told me that the fuel injector fluid was likely the cause for the check engine light, saying that the computer told him that the fuel level was too rich or something like that (he also mentioned the oxygen detector).

Was he bs'n me? Or could this be a legitimate cause for the check engine light to come on? It just came on again this morning (after driving the car about a week with the light off). I am about to go to a mechanic (or a dealer if they aren't TOO expensive) to see what the error code/cause is because the car is still under warranty (engine & tranny). I just wanted to make sure that it isn't too far fetched that the check engine light is caused by the fuel injector fluid.

 

More than likely the first check engine light, too rich condition, was likely caused by a faulty o2 sensor and not the fuel system cleaner. I have never heard of a cleaner causing a CEL before but that is just my take.


Andy

 

Personally, I've never heard of fuel injecting fluid doing that. If you have an Autozone near you, they do free checks on the check engine light.