Failed emission test

[Niclas P]

Was doing the yearly inspection today and failed on the emission testing. I had low (zero) readings on HC and CO but a lambda on 1.29, which is extremely high. The car was ran about for one hour before the test and we test drove 2 times with measuring after both, still high on lambda. The car starts and idles smooth, no check engine light, no soot in the tailpipes, no smoke.

Anyone have any ideas what might be the problem?

[Izzy]

How many miles on it? What year? You may need O2sensors

[Loren]

How many Km on the car?

You may need new O2 sensors as they degrade over there lifespan.

For US cars the PST2 has a test - if you don't get 5 happy faces then you won't pass emissions.

I don't think RoW cars have the vent test.

[Niclas P]

How many Km on the car?

You may need new O2 sensors as they degrade over there lifespan.

For US cars the PST2 has a test - if you don't get 5 happy faces then you won't pass emissions.

I don't think RoW cars have the vent test.

It has 73000 km.

[Loren]

A little early for a sensor failure but I would get someone with an OBD II tool that can graph and show the O2 sensors voltage. My guess is that one or more of the sensors is not working like it should.

Also, are you sure your CEL light is not removed or burn't out. Does it come on when you turn the key to the on position?

[Niclas P]

The CEL light is working. Could it be as easy as a air leak in the exhaust system ?

[jcorallo]

How many Km on the car?

You may need new O2 sensors as they degrade over there lifespan.

For US cars the PST2 has a test - if you don't get 5 happy faces then you won't pass emissions.

I don't think RoW cars have the vent test.

Hi Loren,

I have access to a PST2 now - where do I find the above status check screen?

Cheers,

Jules

Edited June 5, 2007 by jcorallo

[Loren]

Go to your model (996) then to DME. Once you have the DME tests scroll down to Short Test.

[jcorallo]

Go to your model (996) then to DME. Once you have the DME tests scroll down to Short Test.

996? I have a 986! I dont recall seeing a DME Tests section - but I'll have a look tonight.

Cheers,

Jules

[Loren]

Go to your model (996) then to DME. Once you have the DME tests scroll down to Short Test.

996? I have a 986! I dont recall seeing a DME Tests section - but I'll have a look tonight.

Cheers,

Jules

You posted in the 996 forum.

Just go to the 986 section - it has the same test.

[Loren]

The CEL light is working. Could it be as easy as a air leak in the exhaust system ?

I think you need someone to run the tests on your O2 sensors.

[jcorallo]

Go to your model (996) then to DME. Once you have the DME tests scroll down to Short Test.

996? I have a 986! I dont recall seeing a DME Tests section - but I'll have a look tonight.

Cheers,

Jules

You posted in the 996 forum.

Just go to the 986 section - it has the same test.

ahh- :oops: - thanks I'll look tonight!

Cheers,

Jules

[Richard Hamilton]

I don't get any test options on my vehicle in the DME. Mine is RoW version 5.2.2, so maybe it is only available on US cars. That's a shame as it would be a useful function.

[Niclas P]

The CEL light is working. Could it be as easy as a air leak in the exhaust system ?

I think you need someone to run the tests on your O2 sensors.

I have an appointment with the local Porsche garage on Monday. They will support doing the troubleshooting.

[Niclas P]

The CEL light is working. Could it be as easy as a air leak in the exhaust system ?

I think you need someone to run the tests on your O2 sensors.

I have an appointment with the local Porsche garage on Monday. They will support doing the troubleshooting.

Picked up the car this morning. New spark plugs was the solution. The lambda value at the test station was 1.000 when tested later today. By the looks from the plugs it was amazing that the car would work as good as it did, probably they were never changed.....