Q5 EM light on?

[JonHolmezy]

Hi,

newly converted to Audi from BMW with a 2011 Q5, should have done it years ago! Its a great car!

BUT, I have a slight niggly problem with the Engine Management light coming on. I suspect it was an issue when the (non franchised) dealer had the car and he just reset the EM to do the MOT and sell me the car (but I'll never know for sure!).
Anyway, had the Q5 about 2 weeks and the light came on. I had a diagnostic done by an independent garage before taking back to the dealer so I knew that the fault was "NO2 Sensor 2 Bank 1". The dealer ran his own diagnostic and confirmed that that was the fault, plus there was also a fault recorded on the EGR. I assume that the dealer just reset the EM and off I went. 2 weeks later, the light came back on, took it back and the dealer confirmed that its the "Oxygen sensor" which I assume is the same as before?

He's kept the Q5 and says that he's rest it again, and is going to "drive it about for an hour or so then check it again".

Suppose my question is, is this going to fix it? I think that it needs a new sensor, and that the dealer is doing his best to avoid sorting it permanently? I don't want to be taking the Q5 back every 2 weeks for him to just reset the EM, is it an easy fix?

Jon

[zollaf]

welcome.
yes, there is a problem, thats why the eml comes on. switching it off isn't a long term cure. tell the dealer to fix it. if he doesn't then take it to a main dealer to be fixed and send the selling dealer the bill.

[JonHolmezy]

Hi,
yes, I've asked for it to be fixed rather than reset, this time, its obviously an existing problem. I was after a bit more techy info, ie what the sensor does, will changing it solve the issue, how long a job it is, cost etc etc so that I could counter any statements made by the dealer?
Resetting seems to only mask the problem for a short while, then the light comes on again so I need it fixing!!!

[Rob69]

Jon
There's loads of info about o2 sensors online, but generally they last along time, if he's got any diagnostic capability he should be able to check its output before assuming it is goosed and changing it. it is likely to be an indication of a fault elsewhere, rather than the fault itself though. His statement of driving it for an hour to see what happens suggests to me he doesn't have any diagnostics though and he just has a code reader / reset tool he is plugging in.

What the Home Mechanic Needs to Know about O2 Sensors (http://www.autotap.com/techlibrary/understanding_oxygen_sensors.asp)