Emissions light on but car seems fine??

[bennno2005]

My engine management light came on Saturday (the emissions light I believe on the right hand side). I understand its usually a coil pack / 02 sensor of some sort but the car is running perfectly, starts well hot or cold and returned 44mpg on a steady motorway drive back from Lancaster, part way through this journey I stopped for a break and the light was on when I started the car next.

Now if it was a sensor or coil pack the car would surely be using a lot of fuel or running poorly?

Other point that may be worth mentioning is the last tank of fuel I put in was super unleaded (99ron) and I don’t think it was run on it before. No chance that could cause it to come on is there?

Is it an idea to pull the battery for half an hour and see if that clears the light and it comes back on?

Normally I’d take it to a garage to have it plugged in but I haven’t got time at the moment and the car seems to be running perfectly.

Any help much appreciated.

Ben

 

[5678]

I'm chasing down a similar issue at the moment. IMO, once something like that has started, it isn't going away!

I'm in at a dealer tomorrow for a diagnostics check, was surprised that it will only(!) be £49 all in.

 

[bennno2005]

Just had a look at your previous posts, seems your issue is a little different to mine, mine doesn't go into limp mode and performance / economy doesn't seem to be affected at all.

Just wondering if its worth me trying to "reset" the ecu to clear the light and see if it comes on again (if its possible - read something about pulling the battery for about half an hour)

An ecu reset worked in solving a few issues I had with my old 306 GTI 6, although I appreciate these might be a bit more sophisticated.

Or if anyone had any idea as to why its come on in the first place or whether the super unleaded its not used to has made it come on?

 

[bennno2005]

Does anyone know if disconnecting the battery for half an hour will actually clear the codes or not?

 

[Marc.]

Mine throws me an Emissions light every now and again, it's done it with the standard exhaust and cat, as well as when I had my Yozza + decat fitted. In essence, I wouldn't worry about it, every time mine has done it, it's turned off by itself, and each time it's done it when I've changed the RON of the fuel I'm filling with (i.e from Super > Regular, and vice versa).

 

[.Adam.]

This is a problem with a lot of Clio's to be fair.

My old 1.2 had the same issue. Once it begins, it's very hard to get rid of.

 

[Cookson]

Faulty pre-cat lambda sensor?

Swap them round, see if it changes.

 

[Dunn]

Faulty pre cat would lead to poor running and s**t mpg.

best thing to do is to disconnect battery and take it for a run once reconnected.
the emissions light comes on because the post cat lambda is telling you the emissions are high or the cat isnt working.

or pay £30 odd quid at the specialist and get it plugged into a laptop as it could be relating to another sensor maybe.

or try putting it into diagnostic mode by pushing in the button on the wiper stalk and turning on the ignition

cant remember if that will show codes relating to emissions?

 

[bennno2005]

Cheers for replies

Ill try disconnecting the battery and running it seeing if it goes / comes back on again, nothing to lose I suppose

If that doesn't sort it ill have to book some time off work and take it to a specialist.

I was of the understanding that the light doesn't turn itself off even if the problem is fixed and needs to be reset using a fault reader?

Tried the push stalk thing and it doesn't do anything about the emissions light.

 

[5678]

Cheers for replies

Ill try disconnecting the battery and running it seeing if it goes / comes back on again, nothing to lose I suppose

If that doesn't sort it ill have to book some time off work and take it to a specialist.

I was of the understanding that the light doesn't turn itself off even if the problem is fixed and needs to be reset using a fault reader?

Tried the push stalk thing and it doesn't do anything about the emissions light.

FYI, Renault charge £49.99 for a CLIP diagnostics report. I found them to be much cheaper than any of the local Renault specialists round my way.

 

[bennno2005]

^ cheers might be an idea

 

[182lee]

mine came on yesterday, plugged it into my mates diagnostic machine and its the post cat sensor not working correctly, same as yours mine runs fine hot and cold 44mpg usually, ordered the sensor today, my only worry was wrecking the cat if these sensors wernt working or id just leave it, nearly 300quid though for a cat and the two sensors if this doesnt work so the light will just be staying on if this fails, saving my money for the cambelt bloody cars

 

[pendulumx]

You can buy your own code reader for £40 so sod paying someone else £40 to read the code!

My emissions light comes on sometimes. The seller mentioned this in his description but I bought it anyway (good price). I hooked it up to my code reader and it said O2 sensor. Then I took it to the MoT station, and it passed - with the emissions light on - but admittedly only just, with a high lambda reading. The car drives fine and returns good (37 - 42mpg) fuel economy, and the light only comes on occasionally then goes out by itself. On that basis, it seems that the emissions light is quite sensitive and will come on when the O2 sensor is on its way out, but before it begins to have a negative effect on the running of the engine. So to answer your question, an O2 sensor will not necessarily cause the car to use loads of fuel or run rough.

 

[bennno2005]

Just thought I'd follow this up incase anyone else gets similar problems. Had the car in at Birchdown (top blokes) and the error was the downstream oxygen sensor.

They fitted a new Renault CAT fitting kit as it wasnt a proper one on there so was most probably blowing so will see how it goes.

 

[bennno2005]

FYI, Renault charge £49.99 for a CLIP diagnostics report. I found them to be much cheaper than any of the local Renault specialists round my way.

Birchdown only charged me £15 for the dianostic report in the end.

 

[skinz]

Mines is a decat 182, read up that the pipe will trigger light every so often so got a code reader off ebay (£20) and cleared it, not came on since. When it was on the car was running fine with no loss or power or mpg, just french-ness i guess

 

[markyboy85]

The same light on mine came on. I thought it was emissions rated but turned out to be a brake sensor!

 

[M@tt_182]

Mines is a decat 182, read up that the pipe will trigger light every so often so got a code reader off ebay (£20) and cleared it, not came on since. When it was on the car was running fine with no loss or power or mpg, just french-ness i guess

What code reader did you buy? eBay has so many and I wanted to make sure I get the correct one.

 

[skinz]

http://www.ebay.co.uk/itm/051-Renau...iagnostic_Tools_Equipment&hash=item4aae9a69e4

 

[MrBlonde]

I just tried this diagnostic with the stalk button but nothing showed up,do you just hold it down and let it keep beeping and the needles keep moving then turn it on of off again?!..no codes showed up so im just guessing its the post lambda sensor?

 

[RS Charlie]

The on board diagnostic will not always give the right info or any. I'd get a decent OBD reader for piece of mind .

 

[MrBlonde]

I think its most likely the lambda sensor and if I go get a diagnostics its prob going to cost £50?,just for that.Anyone in Essex got a OBD reader or something like that I can use please?.will give you a drink for it of course.

 

[djt205]

Get it code read... your car is OBD2 compliant, one good thing the EU did for us. You're just guessing otherwise. Most places will be able to read the engine ECU codes.

 

[Louis]

Buy a bluetooth reader for your phone. Plenty of threads on here about them and about 5 quid on ebay. Great item and just work with torque on your phone.

 

[djt205]

Yeah and post the result here, code readers can be a pain if you don't understand how the thing works.

 

[MrBlonde]

Code came up 01-01 which is MAF,but the clio doesnt have a MAF.so i think i may of not put the map sensor back on properly when i changed the plugs a couple of days before.Cleared the code & the light has not been back on since,fingers crossed!.so if comes back on prob need new MAP sensor.