A4 2.0 tdi 170 misfire


Registered User
Aug 5, 2013
Reaction score
Hi all, new to the forum so be kind if this is a stupid post.
just purchased an A4 2.0 tdi 170 Avant for my wife and it is now misfiring especially quite bad when under heavy load.
Just done 106k miles 2007 model.
I have rung Audi customer services and they say the injector recall has been done in 2012.
Any common faults for causing misfires? Was thinking injector or maybe fuel filter.

Was thinking to book it in at my local dealer but guessing it will be quite a pricey labour rate.


As you suggested.... I would change fuel filter first and see how it goes.
Fuel filter, injector loom, injector, some injectors haven't been fitted too well either, its not beyond possibility one is faulty again, I guess if filter doesn't help, you'll have to find which cylinder, maybe move injector between & see if fault follows, its one of those pita faults tbh.
Hi Andy, I had to speak to Audi UK a few weeks ago to find out if my injectors had been replaced under recall. They told me that replaced parts carry a 2 year warranty so if it does turn out to be an injector failure then ask them about the warranty. I hope it's something simple.
Thanks for the replies, I'm going to order a fuel filter and get it fitted later today and see if that improves things. Fingers crossed that's all it's going to be :)
Changed fuel filter yesterday, the fuel in the filter was really black, but looked dirty not like engine oil.
Road tested but was still misfiring, remembered someone saying about disconnecting the injectors and reconnecting and tried that.
Disconnected at the multiplug at the back of the rocker cover and reconnected (all looked fine), re tested - now she's flying!!!
Runs perfectly with no misfire. Not quite sure what disconnecting and reconnecting the injectors does but it certainly worked in this case :)
A diesel purge may have been an idea aswell to clean out the injectors a little as I suspect the filter hasn't been done in a long time to be so black fuel & may have left crap in the injectors, but anyway its working now, so good for you :)