MOT FAILURE - EMMISSIONS

[Forren]

Hi Guys,

About a week ago the car came up with the engine light (square box with zig zag lines in it) and went into limp mode, i had to get the RAC out he advised to get the post cat lambda changed. The light then went off after leaving the car for a few hours, and it drove 2 hours home from Stockport without the light coming back on and hasn't come on since. It was a horrible rainy day so that might have caused that issue i dunno.

I got the post cat lambda changed and then took it for MOT as its due. My 2004 Clio 182 failed its MOT - On emissions - it should be 0.2% Co2 mine coming in at 0.790%. It has a custom exhaust on it that's a year old, it is not a decat. The garage are telling me i need to replace the manifold to one with a cat converter in it?! Read about and can't seem to find anything about this, they also trying to tell me my car should have the double barrel cat (is this not a 172 part?).

Any ideas what to do as i'm not really sure this garage is talking sense seeing as i can't find any info on what they're advising me to do.

Any help greatly appreciated, i'm based in the East Midlands area near Donington Park.

The garage that did the MOT also advised the vehicle was hot before testing, although im not sure it was hot enough as it had been left at the garage for the day.

After reading various threads i've seen a few things advising about a temperature sensor making it run rich, my temp gauge is always one notch below optimum. could this be the issue?

Cheers

Alastair

 

[Amos91]

A couple of thing...

1) The postcat lambda only monitors exhaust emissions, it does not effect how the car is running and if this is definitely what was changed your original fault is likely to be present.

2) Have a look under the car and see if it has a catalytic converter. For the 182 this is a single cat, looks like this and will be attached to the manifold:

3) The temp gauge should rise to bang on the middle and stay there, if it drops slightly as you're driving along its likely the thermostat is stick, you'll need to replace this with a genuine partk.

4) Post up a picture of the full emissions report as provided by the garage.

 

[Forren]

A couple of thing...

1) The postcat lambda only monitors exhaust emissions, it does not effect how the car is running and if this is definitely what was changed your original fault is likely to be present.

2) Have a look under the car and see if it has a catalytic converter. For the 182 this is a single cat, looks like this and will be attached to the manifold:

3) The temp gauge should rise to bang on the middle and stay there, if it drops slightly as you're driving along its likely the thermostat is stick, you'll need to replace this with a genuine partk.

4) Post up a picture of the full emissions report as provided by the garage.

Thanks for the reply bud,

1) yes definitely the post cat lambda. looks like i'll need a pre cat lambda then?

2) Yes the car does have a cat

3) thermostat needs replacing then, best place to get one?

4)

 

[JB21]

Do you still have the old lambda sensor you took out? If so try it in the pre cat position as you may find there's nothing wrong with it and it may solve your issues. Really easy to change as well just apply loads of penetration oil before you attempt it.

 

[Amos91]

I'm not sure if its a lambda issue, often it would fail across the board if the lambda is playing up. Someone with more knowledge will probably help on that!

The cat you have is not genuine/standard, I wonder if its not performing correctly... did they get it hot during the test?

Thermostat is here - http://www.renaultpartsdirect.co.uk/product/renault-clio-172-thermostat-seal/

 

[R3k1355]

Yea it's usually the pre-cat lambda that fails not the post-cat, helpful RAC man f**king you about there!

 

[Amos91]

How far does the temp gauge rise? I'd say its either the thermostat making it think its cold & running rich or a faulty cat.

 

[McGherkin]

Usually Pre Cat Lambda that fails, as above. How's your MPG?

Also there's a possibility that the cat is just s**t - it's not OE.

 

[JAParker]

Slip them a £20.

 

[Forren]

I'll try the old lambda sensor that was took out in the pre cat position.

Temp gauge only goes as high as one notch below optimum and stays around that mark. Like this

Haven't noticed any difference in MPG tbh? I get about 30-35mpg?

 

[McGherkin]

That low is likely to make it stay on cold map IMO.

MPG rules out the precat lambda - usually the MPG deteriorates when it goes.

 

[Forren]

What ye reckon then lads, new cat? MOT runs out on Wednesday

 

[Amos91]

It's the cat or thermostat. One of the smaller breakers should be able to send a used cat for around £50-60. Obviously the thermostat needs changing regardless so that would be the first port of call.

 

[bloke]

i'd say they've rushed the fast idle test, had a few that need a minute or so on fast idle before co comes down enough to be a pass.

 

[smac4494]

That's not an original cat. Tbh a double cat (which is a 172 part) would be better than what you've got.

 

[klm182]

when my car failed the mot..they said it was the lambda senor.i was down to 13 mpg..i also had the temp gauge not going to the center,a year after, i replaced the temp senor ,it was fine..

 

[klm182]

my mot the other week was.. CO = 0.00,HD = 15, lambda = 1.030 on fast idle, natural idle was CO= 0..says the engine temp shown warm , i take mine to a council place,they do taxis ,costs abit more,they dont rip off,they are are not allowed to fit parts....will a faulty temp senor, burning more fuel to get the engine warm? .why didn't they notice your temp gauge not being in the middle?

 

[RS Charlie]

If you ask a question you will get many different replies. My gut feeling however is that the cat is to blame (being a cheap pattern item by the looks of things) and possibly your thermostat being knackered. If it were me I'd get a genuine cat, with a secondhand item being fine and either a genuine thermostat or one made by Thomson; I have not had much luck with pattern thermostats in other cars lately.

I'll try the old lambda sensor that was took out in the pre cat position.

Temp gauge only goes as high as one notch below optimum and stays around that mark. Like this

Haven't noticed any difference in MPG tbh? I get about 30-35mpg?

Almost certainly the cat in this case if your MPG is fine. The thermostat however would not help matters. Mine with a knackered thermosat used to slightly higher than that but not by much. The temperature sensor I ruled out; the last owner changed it with no success. The car now runs better when warm.

If it were me I'd try elsewhere if you catch my drift. I've been bitten by pattern cats before ; sometimes when I have bought them (yes, I should not have been so tight).

 

[Forren]

Yeah i'll have to try find a genuine cat now - not had much luck finding a second hand one thats anywhere near me really. what about these sports cats?

 

[McGherkin]

The OE cat is a sports cat anyway.

 

[Forren]

Sound, just bought CAT

 

[bloke]

I've got a cheap aftermarket cat that I use for mot's and never had a problem with it.

Still say the issue is them not taking the time to do thefast idle test.

 

[Forren]

Also - it failed on the N/S CV Joint Gaiter? Reading around people are saying its gonna need new drive shaft, can i not just replace the gaiter?

 

[Jonz]

Any factors will sell CV boot kits they cost about £6-8, they come in split and stretch boots, you'll want a split boot that you glue the slit together unless you know someone who has the tool to fit the stretch boots (they are better and last way longer). Both kits come with the clips that have to be squeezed on with a pair of thin pliers.

That said though unless the boot itself is knackered, you can just tie clip the boot back on which is what I done for my MOT or buy just the proper clip for it for about £1.