Excess pollution/coolant sensor (done a search but need further info please)

[777cupra]

Hi everyone, I've already done a search but wanted to try and clarify a few things.

Basically today my engine warning light/excess pollution light has come on and stayed on. It is stationary not flashing.

Like I have said I have done a search and found out that it could be "a fault anywhere light", so I am just trying to narrow down the possibilities as I'm currently at work, and I don't own VAGCOM or know anyone who does.

The main contenders for causing the light would seem to be

• Coil packs
• Coolant Sensor
• Lambda Sensors
• Maf Sensor

I don't think it's a coil pack as the car is still running fine, I haven't noticed any difference. Also I've read that the light flickers or flashes when coilpacks are gone.

It could be a coolant sensor, but I'm unsure to firstly where it is? and secondly not sure if this sounds stupid, but if that sensor wasn't working would my temperature gauge also not work? It seems to be working fine and the car isn't over heating or anything.

So this leads me to think that it could possibly be a lambda sensor, and from what I have read there is one before and after the catalitic converter. How easy are they to get to and also to change?

Then there is the infamous MAF sensor, but as the car is running fine I do not think that it is that?

I have noticed recently a slight sound like the exhaust might be blowing a bit, which again leads me to think that could affect the lambda sensors (am I right?). Other than that the car is running fine, and due a cam belt service soon.

Just for reference I have a 2001 Leon Cupra with engine code AUQ. No mods to the engine except a smooth airbox, which was done months ago!

Any help much appreciated, as my next day off from work is Sunday, so can't book my car into the garage, and also as i mentioned before I don't have VAGCOM.

Thanks

 

[smoothuk]

well you have highlighted all the problems i would have said, but without VAG COM, i would say you wont get an answer, but if your lambda in the DP has gone, depending on what is wrong with it, it will put the light on, i have had 2 in my LCR, the 1st made the car drive like crap, stuttery etc, and i changed it, the one that has the light on at the mo was done by a monkey at the garage when taking my DP off to be welded, now i know what is wrong with it, but the car funs fine, and really pulls, as if it is not a problem, i can clear the code and it is back immediatly. So....sounds similar if you say no other symptoms. Maybe put a request in the VAG COM requests section and see if someone can spare you a few mins one evening after work just to check it out for you.

 

[777cupra]

cool thanks for the reply, how much was a new sensor? and how easy was it to replace?

 

[777cupra]

Just found out that when the car is cold, the light does not come on. It may come on when warm, but I only just moved it across the car park at my work just now.

Would it be reasonable to assume it's something to do with the coolant sensor then?

anyone any ideas

 

[777cupra]

anyone any ideas? just out of interest where is the coolant sensor?