General Cinq failed on emitions - ideas ?

[big-ernie]

Hi Guys,
My wifes Cinq sporting failed on emitions and rusted back exhaust box. The guy at the MOT centre said that if we got the back box fitted, it might pass. I've noticed that tickover slightly lumpy, but no great misfire.

The readings are :

Fast idle test Fail
Engine speed = 2829 rpm Pass 2450 2950
CO level at 2829 rpm = 0.00% Pass 0.30
HC level at 2829 rpm = 8 ppm Pass 200
Lambda at 2829 rpm = 1.05 Fail 0.97 1.03

Second Fast idle test Fail
Engine speed = 2793 rpm Pass 2450 2950
CO level at 2793 rpm = 0.00% Pass 0.30
HC level at 2793 rpm = 5 ppm Pass 200
Lambda at 2793 rpm = 1.04 Fail 0.97 1.03

Natural idle test Pass
Engine speed = 886 rpm Pass 750 950
CO level at 886 rpm = 0.00% Pass 0.50

Any thoughts where to start guys, or do you think changing that back box might have sorted it ?

 

[blu73]

when was it last serviced?
the back box will effect it but a good service will never be a bad thing

 

[gazzaman2k]

change lamba? new airfilter and plugs

 

[blu73]

oil & filter, new HT leads, they all make a difference but like i said depends on how well serviced it has been in the past. It could even be a damaged CAT.

 

[fingers99]

Lumpy idle could be plugs, leads, coil pack or HG.

I'd do a full service plus leads, see how the idle is.

 

[rallycinq]

Its missed by a small amount, so a damn good thrashing might sort it, assuming the service history is up to date.

Cheers

SPD

 

[Pep0]

I'd agree with David, new plugs, new air filter, lots of proprietary goo on any holes in exhaust long run to stabalise the learning of the ECU and then it will pass.

But replacing the rear exhaust will be necessary so you might as well replace rather then short term repair.

Noel