Hi All

This is my first post, I hope I explain ok and thanks to everyone who posts on here to give advice.

I've had some success in following and understanding fault codes i've searched for but now i'm baffled. Please can anyone help?

Car seems to start and run fine until it warms up then it turns into a real dog. It judders badly especially under load.

Recent fault codes

16485- MAF implausible signal.

17526 Lambda Bk 1 Sensor 2 heater open circuit.

16524 Lambda Bk 1 sensor 2 slow response.

16556 System too rich Bank 1 sensor 1.

17698 CTS at radiator outlet.

I changed Lambda Bk1 sensor 2, codes stayed the same.

I then changed the CTS at radiator outlet which fixed some codes.

Now I have 16485 MAF, and 16556 system too rich Bk1 sensor 1.

I'm sure someone will say replace the MAF then! Well I did three months ago but the code was there back then and the car still ran fine. I've disconnected the MAF and it makes no difference whatsoever.

I don't understand why the car runs great until the temp guage gets to approx 90 degrees then it starts to judder, the further I travel the worse it seems to get. I also changed the Engine Temp Sensor (green one with four pins).

Could the upstream Lambda be giving a false reading? I assumed it to be giving helpful info

Any Suggestions would be gratefully received before I have to spend a fortune at the dealer.

Thanks for reading

Glenn

Edited 5 December, 201114 yr by Funkster

What make of CTS did you get? There's a problem with aftermarket ones and OE are the only reliable ones.

Agreed a new VAG CTS is the only one I would trust to work. Temp related running probs nearly always turn out to be the CTS.

The Radiator outlet one was VAG but the Engine one/four pin one wasn't. It is febi-bilstein.

I should probably start there then I guess. Thankyou.