Oh no, failed the MOT

[jasst]

Will go over it and see if I can find any sort of leak, one thing I have just noticed, it says gran turismo sport on the emissions sheet, could they be testing to the wrong set of parameters? and interested as to why those figures make you think that, as it's all confusing to me.

 

[Oneball]

The limits aren’t model specific.

You’ve got high CO which can be due to running rich

You’ve got high lambda which shows too much oxygen in the exhaust.

The two shouldn’t really happen together unless you’ve got air getting in after the MAF so it’s incorrectly metering the fuel or air is getting sucked into the exhaust so the lambda is providing an incorrect feedback.

 

[jasst]

The limits aren’t model specific.

You’ve got high CO which can be due to running rich

You’ve got high lambda which shows too much oxygen in the exhaust.

The two shouldn’t really happen together unless you’ve got air getting in after the MAF so it’s incorrectly metering the fuel or air is getting sucked into the exhaust so the lambda is providing an incorrect feedback.

The limits aren’t model specific.

You’ve got high CO which can be due to running rich

You’ve got high lambda which shows too much oxygen in the exhaust.

The two shouldn’t really happen together unless you’ve got air getting in after the MAF so it’s incorrectly metering the fuel or air is getting sucked into the exhaust so the lambda is providing an incorrect feedback.

Thank you, still learning at 59!

 

[lambertius]

The limits aren’t model specific.

You’ve got high CO which can be due to running rich

You’ve got high lambda which shows too much oxygen in the exhaust.

The two shouldn’t really happen together unless you’ve got air getting in after the MAF so it’s incorrectly metering the fuel or air is getting sucked into the exhaust so the lambda is providing an incorrect feedback.

Can confirm high CO is usually caused by running rich or/and running cold. I dunno how the secondary air system on this car works, but generally speaking the point is to allow more air in to complete combustion of hot exhaust gases. Taking a guess I'd say that has probably got something to do with the high CO.

It won't hurt or cost any real effort to clean the MAF and check for vacuum leaks between it and the manifold. I'd check for leaks in the secondary air injection on the exhaust, and if you really get stuck you can wrap the exhaust up till the Cat to keep the gasses hotter to improve the Cat's efficacy.

Glad we don't have that here!

 

[jasst]

Well, passed this morning, secured a complete set of cats from Lithuania complete with centre resonator for a not unreasonable £600, fitted the cats but left the 'H' pipe on, passed ok but still a high lambda reading, but within limits, question is can I be arsed to get it up on the ramps again and put the sports cats back on! Probably will as javing had one episode of cat breakup with catastrophic results, dont really want yo go gown that route again.

 

[philw696]

A pass is a pass.
Still might have a very small leak on a joint

 

[Wanderer]

A pass is a pass.
Still might have a very small leak on a joint

Won't that make your doobie go soggy and taste of piiss, man?

 

[jasst]

A pass is a pass.
Still might have a very small leak on a joint

Yeah, must be a leak somewhere, that was their conclusion as well, obviously cant be that bad or they would have found it when checking underneath, you'd have thought anyway.

 

[TimR]

Mine's even closer than that @ 1.028...!
Keep us posted if you find the problem...

 

[alfatwo]

Just leave everything as standard, what's the point of faffing about, you cant use the performance nowadays anyway!

Dave

 

[TimR]

Actually, IMO it would be helpful if the MOT tests would elaborate on the findings...
Are the probes really that dumb ?
Its not a very clever test IMO... choosing to place the probe in one or the other of a twin outlet box, modified for a little noise that might then favour one outlet over another could create an ingress of fresh air in the chosen tip...
I ve read of a few Porshe guys stuffing a rag in one side to stop the reading being skewed like this..of course, if we were able to see the 4 gas test numbers, assessment of the actual running environment would be more possible...

We're just dumb punters- ours not to reason why....

 

[rs48635]

glad you got the pass.
Surely there was a leak with original setup as CO has gone back down to zero.
Noticed different range on the lambda between test stations. The difference was no help to your car at 1.049 but odd for test on the same car.
test 1 0.980 to 1.020. F10 JJP. maserati
test 2 0.970 to 1.030. F10 JPP. mini clubman

 

[jasst]

Just leave everything as standard, what's the point of faffing about, you cant use the performance nowadays anyway!

Dave

Having suffered catastrophic cat failure already, want to minimize any chance of it happening again.