Exhaust emissions

[poweller23]

Has anyone had problems with exhaust emission on a standard exhaust system? I did a emissions test on my Twingo Wednesday night and it fails on the fast idle test only on the co2 level it's meant to be no more than 0.20 and mine is 1.48 the lamda is fine on it. It was at Renault on Thursday for the lower arms to be done witch they did no problems I asked them to check the emission as well at the same time. They later came back to me and told me that they checked the fault memory and there was no codes stored and said if they was a problem it would of shown when the checked it do I no have the printed the emissions test off as prof so back to Renault it will go once I got time to book it back in.

 

[poweller23]

Also I took the coils and plugs out of it to night and checked them as I no people are having faults with them and there all ok

 

[maggi200]

How do you drive the car? Not sure the sensor will throw a fault up necessarily but could still be the issue.

 

[poweller23]

Normally really I do drive it hard from time to time but I always let it warn up and cool Down properly

 

[poweller23]

Tbh I couldn't see it being a sensor as the lamda was fine I think it be more like the cat breaking down or a sticking valve inside the head not opening quite far enough when on fast idle

 

[maggi200]

Valve possible. See the condition on Neil's spare head.

Cat or sensor is my bet personally. Ktec manifold?

 

[poweller23]

Everything on my car is standard no ktec bits on it yet lol

 

[singlespeed]

Did you mean CO rather than CO2 being out of range?

What grade of fuel are you running?

 

[poweller23]

Yh that's the one my mistake and I run normall 95 from texaco never used supermarket fuel as its a waste of time I don't like it one bit

 

[singlespeed]

what age, condition is the airfilter?

Was the engine allowed to fully warm up, untill the fan kicked in?

High co is running rich, so too little oxygen (air) or too much fuel, possibly on the warm up cycle

 

[poweller23]

Had the air filter out the other day and it looked like new and I blew it out with the air line as well i let it run up until the cooling fan cut in and I did the extended emissions test witch you have to hold the car on fast idle for 3minutes

 

[singlespeed]

Lambda sensor before the cat failing, causing the fuel ratio to be too rich.

Hows your fuel ecomomy? Average or poor

 

[poweller23]

Well I get about 200-250 miles to a tank fuel that's running forwards and backwards to work but when I took it on a run to FCS I did really well on fuel I used 2 blips to 150 miles so pretty average I check the lamda sensor tomorrow to make sure it's switching

 

[singlespeed]

Theres a bit about the lambda sensor hi/lo switching here
https://www.picoauto.com/tutorials/emissions-components-actuators.html

Just been having a read up as its something I've not looked at before. I knew what they did but not how they do it :?

 

[poweller23]

Thanks for that I going to take it to renault as its still under warranty and see what they say this time i I get no joy this time I have to contact RUK

 

[poweller23]

Right I finally got around to having a look at my car to night for poor emissions, after renault telling me there is nothing wrong with my car. I checked the lambda sensors to make sure they are switching they was working correctly. So I thought I change the spark plugs I didn't do this before as they looked fine when i had them out a couple of months ago, and there not due to be changed yet as its only done 24k and is ent 3 years old yet. This has fixed my problem of poor emissions but I have also noticed water getting into number 4 cylinder . :-( so back to Renault it will have to go yet again.