Does your Cupra smoke much out the exhaust?

[The MoffMeister]

mines been ok since it started the patchs

 

[Deleted member 20376]

mines been ok since it started the patchs

 

[lee_woollett]

yes lambda sensor will make a massive difference to economy and fueling if its not working right. I used to work for an exhaust manufacturer and i got some time to learn about how these work, also dad is a mechanic and i've seen the results of them fooking up. I've seen a car which was overfuelling, the lambda got a bit of fuel on it which caused it to stop fuel being injected as it thought there was too much......

Too much or too little fuel is deadly combination for a turbo'd car...... mmm melted pistons

 

[kineticz]

WTF... :O they told me it would cause no problems to have the lambda in after a decat??

 

[LEE69]

Who did?

 

[kineticz]

The guys at Performance torque.

 

[LEE69]

Have you got both lambas in still?

 

[kineticz]

Yep...

 

[LEE69]

The second one is getting the wrong reading as the cat as been removed.

 

[kineticz]

I suppose that is what is causing my overfuelling? Like I said, I was told it would be fine. If I remove it, would that be safer than having it in? i.e. will it revert to basic settings?

 

[LEE69]

Yeah without a doubt that is it as it is looking for a reading from a car with a cat, you can just remove as it will the same as now.
It needs mapping out.

 

[kineticz]

Oh dear Well its only been fitted a couple months so if I get it mapped out the next couple weeks should the engine be undamaged?

 

[kineticz]

Just a thought but doesn't the post cat lambda just monitor the condition of the cat? If so, how would that affect fuel mixture? Thanks

 

[LEE69]

I subscribe to threads

Yes it does but if it gets the wrong reading, it messes up the fueling as you are finding out.
Stop wasting your time we now know the problem, the cure is getting it mapped out

 

[DannyC87]

iirc its the pre-cat lambda sensor that controls mixture; the post cat as you say is to monitor the condition of the cat; and will out the eml light on if it reads too high - a spacer can be bought to stop it triggering this light.

 

[kineticz]

See you are both saying different things which doesn't help

 

[LEE69]

Try a spacer and let us know, but you still have a fuelling issue.

 

[The MoffMeister]

your tuner should be able to sort that

 

[kineticz]

Try a spacer and let us know, but you still have a fuelling issue.

I THINK the error code on vagcom might actually have been referring to the pre-cat lambda as it mentioned heat. So maybe that needs replacing

I'll wait until I take it back to P-torque and I'm sure they can sort it as said. I've actually thought mpg has been quite good but if it will turn out to be even better then I look forward to it

 

[LEE69]

You have un-burnt fuel at the rear mate, never a good sign.