VR6 High CO / Lambda

[993turbo 0]

Had an MOT done to one of my VR6's, and it showed a high Lamba and CO.

Its an early dizzy VR6. ......

Lambda @ 1,080

CO @ 0,9 - 1,0 %

Any ideas anyone???

[993turbo 0]

these are measurments taken with a probe at the exhaust tips...

[993turbo 0]

What are my variables here????

I take it there are no adjustments to be made?

-Lamda sonde?

[russj249 2]

You cannot adjust anything as the car should do it for you. Because it isn't doing this, there could be a problem with the O2 sensor, the CAT or a misfire.

If there was a misfire you'd expect to see the HC (hydrocarbons) high too.

There is something called Red X that you can put in with the petrol and it cleans out injectors. Run a bottle of this through before taking it for retest. Also give it a good thrash and clean the system out and make sure it's red hot before they do the test again.

As for the lambda it is probably related to the CO but can also be make high if your exhaust has a pin hole leak or blowing anywhere.

Might be best to check out the O2 sensor readings on VAG-COM or similar software and see if there is any fault codes.

what condition is the rotor inside the dizzy? and plugs etc? has it got a misfire?

[993turbo 0]

Rotor / Cap / Plugs / Leads are new.

No fault codes.

What reading am I looking for ref the O2 sensor...?

[russj249 2]

I can't remember what the figures are to be honest with you. I think on VAG-COM they should be around 1.000 and fluctuating, but get somebody else to confirm this.

If you can see the numbers on VAG-COM, it should be around 1.000 and moving constantly in very small amounts, and move significantly when revved. If it is sitting at exactly 1.000 it'd identify a problem. Mine did this and didn't show up a code.

If not this could identify a problem with the CAT, but definitely get somebody to check properly as CAT's aren't cheap. Has the car had a misfire in the past? If petrol, oil, liquids etc get into the CAT it can damage the precious metals inside, stopping the CAT from turning/aiding the change from CO + Hydrogen into CO2 and Water.

[993turbo 0]

Yeah, on my VAGCOM the Lambda is fluctuationg around 1, a little less, and alittle more, but fluctuating up and down.

VAGCOM is still not dispalying any codes.

Can it be the CAT?

The lamda would not be high because of the cat... ? CO, yes, possible.

[Rikki 2]

Where in vagcom do you check lambda?

[gavinvr6 0]

my car failed it's emmisions. was told mine is 0.6 and should be below 0.2, and is only showing isv as a fault, despite fitting a replacement/used one, but mine is a coil pack obd1 so might be different.

i've been advised to fit a new filter as mine is rotten plus run some fuel cleaner/injector cleaner through it, check your filter isnt dirty or blocking up then run some cleaner through it, try fuel system/injector cleaner and/or 10k boost, im gunna be putting fuel cleaner/injector cleaner plus 10k boost through mine tonight if i get home at a sensible time if not i'll update in the morning if any visibly noticable difference

[russj249 2]

my car failed it's emmisions. was told mine is 0.6 and should be below 0.2' date=' and is only showing isv as a fault, despite fitting a replacement/used one, but mine is a coil pack obd1 so might be different.

i've been advised to fit a new filter as mine is rotten plus run some fuel cleaner/injector cleaner through it, check your filter isnt dirty or blocking up then run some cleaner through it, try fuel system/injector cleaner and/or 10k boost, im gunna be putting fuel cleaner/injector cleaner plus 10k boost through mine tonight if i get home at a sensible time if not i'll update in the morning if any visibly noticable difference

[/quote']

maybe the only time it's advised but give it a good thrashing .. make sure all the sh!t is blown out the whole system. Make sure it's red hot too before they test it. Also check for no misfire or air leaks etc. If ISV is coming up as fault, it might be worth putting some carb cleaner, de-greaser or something in it, shake it around and do this a few times. Make sure it's dry before fitting or car will rev plus don't really want any liquids being chucked into cylinders.

as for your readings.. it suggests that you're oxygen sensor is working correct, so can rule that out. Possible causes now could be the CAT or a misfire/air leak. Maybe you could do a vacuum check on the engine at tickover. I haven't got a clue what the figures should be, and every engine will be slightly different but if there was an air leak it'd show a lot below. Plus you might be able to hear a sucking noise. If you can't find anything get somebody to have a check of it and see what they think it could be.

[993turbo 0]

Does anyone have an idea what the vacccum should be at idle?

[993turbo 0]

does anyone have a clue what the vac reading should be at idle?

[993turbo 0]

Took out the CAT and found the following:

:sick:

Its been hot in there :-)

[img width=800 height=600]http://i39.tinypic.com/35hreqt.jpg

From the back

[img width=800 height=600]http://i43.tinypic.com/35kslmc.jpg

Ramining CAT stuff removed, with brutal tools! Now I have a De-Cat pipe :-)

[img width=800 height=600]http://i42.tinypic.com/15qao0z.jpg

A piece from the CAT:

[img width=800 height=600]http://i40.tinypic.com/25s1o37.jpg

Car in the Garage getting ''intensive care''...............

[img width=800 height=600]http://i43.tinypic.com/1zflgy9.jpg

[russj249 2]

Wow that's probably why your emissions are high. CAT is knackered

As for that, it's blocking the flow loads by the looks of it. Might get a fair whack more power from that!

[Rikki 2]

Let us know how it sounds with the gutted cat mate!

[993turbo 0]

Sounds crap with the gutted cat. ''Tinny''.

However, the car passed the MOT with flying colors when I fitted the cat from my other VR.. :-)