Honest

Hi guys,

My car failed emission test and is running really rough, no power in any gears, very diffcult to go up hills.

I am getting the following codes:

00520 - Air Mass / Air Flow Sensor (G70)/(G19)
31-10 - Open or Short to Ground - Intermittent
00523 - Intake Air Temp Sensor (G42)
30-10 - Open or Short to B+ - Intermittent
00537 - Lambda (Oxygen Sensor) Regulation
19-10 - Lower Limit - Intermittent

So far I have changed the CAT and Lambda sensor before the CAT.

I also installed a secondhand MAF a few months ago and changed the plug's about 4 weeks before the problem started.

Please help.

turbo510

Have you tried running with the MAF sensor disconnected?

Honest

Thanks for your help turbo.

I have cleaned the MAF and the first 3 codes have now gone. Car is still running rough and I think it will still fail emission.

I now get this code

00525 - Oxygen (Lambda) Sensor (G39): Signal too Low

Could it be that my new Lamdba sensor is faulty?

This guy has the same problem as me, but no one has posted a solution.

http://forums.vwvortex.com/showthrea...ensor-problems

mime651752

have you tested the O2 sensor yet? If its not bouncing below 200mv and above 800mv the sensor could be "lazy"=bad. Also obvious stuff like fouled plugs could cause a rough idle.

Honest

My Lambda sensor is an aftermarket part from Euro Parts, I have tried two replacement parts from there but still have same problem.

It is defiantly not a bosch, Ngk or Denso part. Can’t remember the name.

Should I buy a genuine one from Audi.

Please help my car has been sat on my drive for months and I do not want to have to scrap my car, if it is just because of Lambda sensor or a minor part.

I have had the car for 7 years now and before the MOT it was very reliable.

4Driver4

Clear the codes, drive car, post new codes.