daley60

Hi everyone
Can you please help.
I have a audi a4 b8 1.8tfsi 58 plate with 62k miles
I have code po171 showing coming on every couple of days I keep clearing it.
Car been in garage around 5 times checked for air leaks saying none there changed 02 sensor front one also had a full service spark plugs air filter and so on.
Now saying could be mass flow sensor.
Car running rough on idle the tick over is fine a little loss of power and hasident and setting of when cold start.fuel seems to be the same
Also has a mobile tuner man check it also he said no leaks and says mass flow sensor.
Any help will be much appreciated.

Nostromo

Check the PCV valve

daley60

Thanks so much for reply.
How can I check if PCV is working alright

Thsnk

Nostromo

Do a search on the site. There's some videos on youtube.

You can hear it hissing with the hood up. Stick a finger on the end of the valve and if there's suction that's bad. It should also be very hard to get the oil cap off when the car is running.

daley60

Thanks for help
I have listened for hissing but can't hear nothing.
Tried getting oil cap off which came off so easy.
Light back on today showing po171 code again.
Is there any thing am missing it's becoming a nightmare trying to resolve this problem.
Many thanks again.

daley60

Hi again

Garage been checking around PCV VALVE saying when they spray brake cleaner says rough idle settled down for a few seconds saying needs new one!
Would this fault bring up code po171
That's all I keep getting every 2 days
Another thing I can see white smoke from exhaust when putting power down
Any help is much appreciated
Thanks again

daley60

Hi sorry to go on
Just had pcv valve checked at garage they said not faulty!
Now I don't know where to go from here.

Thanks