General High CO emissions help please

[cptcuddles]

Car failed MOT today as suspected but would like some advice on the emissions failure and where best to start looking wondering if its the cat. Car also failed on exhaust least at flange between downpipe and flexi pipe so not sure if thats going to be a factor. car is a 2001 1.6 Weekend. Emissions results as below any ideas gratefully accepted car recently had new leads and coil.

fast Idle 2865rpm

CO 0.35
HC 67
lambda 1.011

2nd Fast Idle 2640rpm
CO 0.93
HC 80
Lambda 0.991

Natural Idle 785rpm

CO 0.43

 

[Neverth]

Running little rich.
Simple oilchange could do it?
Airfilter change?

You could check out the MAP sensor on the intake manifold, prettymuch the only sensor on 1.6 to go wrong (with the coolant temperature sensor). The piping is so dirty so it cant read the pressure properly.
But as yours still runs pretty good, my guess is that it is working fine.

For the leak, is it a CAT on manifold or cat under the car. They changed it that year (Euro3).
I can imagine it doesnt like oxygen when it is running hot.
For cat in manifold, it has two lambdas, if either one is before leak, it will mess things up.

Ride it against brakes at full throttle after a long trip on motorway, heats up the cat pretty good.
After that go to get it tested.

 

[cptcuddles]

Thanks for quick reply. Its a Cat on the manifold so both lambdas are before the leak

 

[cptcuddles]

With engine warm i connected ecuscan. Engine temp was 80c and manifold pressure was 430mbar at normal idle and dropping to 280mbar at approx 2000rpm is this normal?

 

[Neverth]

Map should be good as it registers changes, clogged ones are slow or dont do anything.
Temp is fine.

Get the leak fixed, tiny leak rises the oxygenlevel a bit so the car tries to run little richer to achieve perfect ratio.
Change the airfilter too if it has not been changed in years.
I'd say the cat is still good as the HC levels are low.

 

[bpetersb]

Those pressed flanges are horrible! Trouble is they joint the 'expensive' cat and the 'expensive' flexy section. I found a great little local garage her in North Norfolk who found a forged flange in their scrap exhausts, cut out the rotten one and welded the forged one in. Job done for many years to come hopefully.

I agree with Neverth re emissions, oil and filter, check the air filter and a set of plugs if they are anywhere due for change should sort it out.

Good luck

 

[cptcuddles]

Had a bit of a look about today as the sun was out. Filter on the grubby side so will replace what surprised me most was I thought I'd give the throttle a clean so took all the air intake piping off. Amazed at the amount of what looked like oil in the plastic tubing must have been approx 300ml assuming this is vapour mixed with water from air. Also whilst looking at manifold area found I could wobble the o2 sensor from side to side, so tightened this up as well

 

[cptcuddles]

Cleaned all plugs and both o2 sensors which were a bit on the sotty side. Sat with the car connected to ecuscan to see if there were any glaring faults with sensors.
Precat o2 voltage switches but is normally around 0.4V range, postcat shows 0V and remains in open loop until rpm reaches 2000 then it switched to closed loop with voltage at 0V.

After finishing looked at car and saw what looked like black water slowly dripping to the floor, had a look and there is a small hole in the bottom of the oil filter which drips when the engine is running. can actually see where its been blowing back onto the sump whilst driving

 

[varesecrazy]

Cleaned all plugs and both o2 sensors which were a bit on the sotty side. Sat with the car connected to ecuscan to see if there were any glaring faults with sensors.
Precat o2 voltage switches but is normally around 0.4V range, postcat shows 0V and remains in open loop until rpm reaches 2000 then it switched to closed loop with voltage at 0V.

After finishing looked at car and saw what looked like black water slowly dripping to the floor, had a look and there is a small hole in the bottom of the oil filter which drips when the engine is running. can actually see where its been blowing back onto the sump whilst driving

definately time for an oil and filter change then,

dirty oil boils off nasty gasses as it warms,

:idea: so getting the engine hotter to improve results could have the opposite effect,
Charlie

 

[cptcuddles]

Oh well failed the re-test had new air and oil filter, oil change,new plugs still too high CO levels.

 

[loveshandbags]

Oh well failed the re-test had new air and oil filter, oil change,new plugs still too high CO levels.

Sorry to hear that it failed. My 2000 1.6 weekend only passed last feb on the 2nd attempt. At one point it looked like it needed a steering rack. It has 118k on the clock. I'm assuming you used some decent 10w40 oil and new NGK spark plugs. If you suspect that the Cat is gone is there no light showing on ?
How many miles have you done ? If it's excessive unsure if a thicker oil might make a difference. Did it fail by much ?

 

[varesecrazy]

Did you drive it far for its retest?,

ie. did it run well, no missing / coughing,
anything else untoward?

Charlie

 

[cptcuddles]

About 45min drive before re-test. Guy at the test station tested it first again failed then said go for another drive come back in 30mins and we'll have another go. In all we tried three times. Drives fine no MIL lights and no odd sensor readings I did tongue in cheek ask the tester if the gas analyser was working. In all fairness he was bemused as much as I was. He's even offered to unofficially test it Monday for free and will officially do if it passes.

 

[varesecrazy]

thanks,
that's an odd one isn't it,

are the figures pretty much what you got on the first failure?,

or have things improved markedly since the oil change / plug swap?

Charlie

 

[barnsleygit]

As a last resort have you concidered trying CataClean?

I no some people hate the stuff but it did get an old Rover 600 of mine through a couple of years ago

Good luck

 

[varesecrazy]

As a last resort have you concidered trying CataClean?

I no some people hate the stuff but it did get an old Rover 600 of mine through a couple of years ago

Good luck

I thought the CAT gave HC readings NOT CO..??,

I was leaning more towards leaks - BUT the Lambda is not too far off the mark,

Charlie

 

[cptcuddles]

Finally passed.

Couldn't think of anything else to took at, but remembered I had a new injector put in a few months ago, correct part but different to the other three originals. Luckily friend as a fiat he's using for parts and as same injectors as my originals so borrowed one and car finally passed.

Guess one cylinder must have been getting more/less fuel than the other 3 which must have been throwing things out.

thanks for every ones help

 

[varesecrazy]

Glad you got it through,
shame you had to spend quite as much on extra parts,
BUT should be good for a while now..!!,
Charlie