Catalytic Converter Warning Light???

[dadavies90]

Hi all,

Just after some advice regarding my 2010 plate 1.4tsi 160 scirocco please. The orange catalytic converter warning light came on tonight, it stays on which in the user book suggests there is a problem with the catalytic converter. What could have caused this? Could a cat-back exhaust system affected this? Or would a remap cause this issue?

The car is still under warrenty so will contact VW tomorrow but just after some heads up before i go.

Any advice comments welcome.

Thanks

[Cuprabob]

Is the car running OK?

Mostly when this happens it's due to a misfire and the unburnt fuel is picked up by the lamda probe and triggers the light.

Normally it's a faulty coilpack that causes the misfire but as you may have read on other threads the 1.4 twincharger engine has had issues with misfires leading to bigger problems therefore get it cheacked ASAP.

[dadavies90]

The car seems to be running fine, no lack of power or misfires that i am aware of. My first thoughts where the common faults with the 1.4tsi engine but had no signs of this happening. There was a smell of burning when the light turned on which is why i am reluctant to use the car until it is checked out by VW. My local garage are doing a diagnostic on it before i go to VW with it tomorrow.

I hope the exhaust doesnt void my warranty!!!

Thanks for the reply mate.

[dadavies90]

So the diagnostic showed a faulty purge sensor which has now been replaced. This has sorted the light problem so it has cleared any error codes however since this has been fitted I have noticed the car is misfiring!!! It's a 2010 plate, does this fall under those that had common problems with this? Are the misfires due to a spark plug problem?

Thanks

[RW1]

I have noticed the car is misfiring!!! It's a 2010 plate, does this fall under those that had common problems with this? Are the misfires due to a spark plug problem?

Not necessarily....... there are several causes, coil packs, injectors and plugs.

Mis-fire at idle? at speed? at a certain point in the RPM? Mis-fire during warm-up, once warmed-up? Mild misfire or violent judder?
Better description of what you are experienceing would help.

If you prolong using it while mis-firing, then the "hammering" causes damage the piston(s) and leads to failure. The more you let it happen, the more the latent damage is stored up for later, even though the engine problem is sorted soon. Best taking it back in and getting it sorted to prevent engine damage.

C.

[dadavies90]

Thanks for the reply. It seems to happen around 3500 rpm at speed. I notice it when you pull out to overtake etc, there is quite a noticeable judder. Well a few judders. Around town it seems fine, it's the minute you put your foot down it judders and feels like it doesn't want to pull. I hope this can be sorted and won't be a reacuring fault.

[RW1]

That may be the N75 Boost control valve.
http://www.sciroccocentral.co.uk/forum/ ... ols#p91812" onclick="window.open(this.href);return false;

C.

[dadavies90]

Thanks again for the reply. Should this come up on a diagnostic test if I get it tested again? Or is it just a matter of trial and error? Sorry I'm useless when it comes to anything like this.

[RW1]

It should but runing a misfire like you describe is damaging the engine, so they need to sort it.

C.

[dadavies90]

Yeah I'll defiantly stop using it and get it checked. Is there an easy way to check the n575 boost valve or does it just have to be replaced and hope for the best?

Really appreciate your help mate.

[RW1]

Remember these misfires are never what you think they are, so at the distance its the first thought given what you have written.
It would be more useful to see if any fault codes which have been registered to give some pointers what happening to the engine.

N75, check the rubber pipework, can check the operation.......

Check the condition of the three rubber pipes marked with green lines for fitting and leaks.

DSCN7626a.jpg

N75 can be checked for operation using the VCDS Output Tests. http://www.sciroccocentral.co.uk/forum/ ... tput+tests" onclick="window.open(this.href);return false; ..... about halfway down the post. So if you can get someone to help who has VCDS....

You need to take it to the dealers to sort really.

C.

[dadavies90]

I have just checked the pipes marked in green and they appear to be ok. Connected fine and they look like new, no sign of corrosion or anything.

Coming home from work tonight it didn't misfire, doesn't do it every time so really don't know what's causing it!!! Only worry is that the warranty is out which is why I want to some advice so I can say what I believe the fault is. Rather than being ripped off for things that are not needed.

Thanks for the pics, great help.

[voyager]

Could it be the fuel? Can you relate the misfire to where you last filled up because some garages aren't as good as they should be when it comes to fuel/water filtration. Also when garages order fuel they have to make an educated guess at the quantity they need by the time of delivery and have to pay the carrier a penalty if they order fuel they cannot fit into the tanks; many petrol stations will pass part of this penalty to the manager who is usually paid partly on commission so to avoid this penalty some of the more unscrupulous garages have a nasty habit of dumping excess diesel into the petrol tanks and vice versa and I say this as an ex petrol station manager myself. One supermarket close by where I used to work was closed down by Trading Standards a couple of times because of that practice.

[dadavies90]

I've tried running it on v-power and it's still the same. Had a diagnostic at vw today and they said there is no fault, just recommended using v-power fuel! Not happy with that really, must be something up with the car to be misfiring so regularly.

[voyager]

I don't much like the sound of that, I have a 2.0 TSi and it will run happily on either 95 or 98 RON fuel. If it were me I think I'd get a second opinion from another dealer as a regular misfire can never be a good thing

[kenti]

It is probably one of your coils that need to be changed. The coils are often the cause of misfiring. And, even though it should cause an error message in the ECU-log, it doesn't always do that. So if the dealer only check for errors in the ECU-log, they'll most likely believe there's nothing wrong with your car. Have you taken one of the technicians for a spin to illustrate the misfire?

[dadavies90]

I'm not to happy with that either as i believe there must be something up with it or else it wouldnt miss. The main technician took it out but like always it didnt miss during the test so as the diagnostic shown no faults also they blamed the fuel.

It's always the same isnt it, when ever they take it for a spin the problem never occurs!!!