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Technical High CO emissions

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Technical High CO emissions

It only failed the first fast idle and passes the 2nd fast idle as you can see first fast idle is only just failing then once warmed up a bit more it passes 2nd
 
koalar said:
you done the same as me


the fast idle has also failed just doesn't have a circle around it




lambda is Bob on. mixture is correct. So CAT isn't doing its job. Clogged or not hot enough
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only failed the first fast idle and passes the 2nd fast idle as you can see first fast idle is only just failing then once warmed up a bit more it passes 2nd
 
jackwhoo said:
Everything you have posted
Points too excessive fuel is going into cylinders at idle, so much the ecu has reduced the amount of fuel to the lowest limit programmed and the o2 sensor is still reporting fuel rich mixture( 0.9v )


Can you remove the fuel rail with the injectors still attached and the fuel feed pipe still attached?

Does the car have a fuel pressure regulator attached to the fuel rail? Or is the fuel pressure regulator part of the fuel pump?
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Will do this tomorrow as nothing open to buy new O rings today. Gonna also buy some cat cleaner and put high octane fuel in and give it a blast on the motorway.
 
koalar said:
yes there loads. But its not what happening here. I thought you only had a problem at idle. Just Google idle, throttle position sensor, mot and emissions. But to me is a red herring as its also failed at fast idle and the lambda is bang on where it should be.


So you have the correct fuel to air but still High CO but HC are okay. The normal "fix" is to get the CAT red hot before the test.
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The mot emission lambda number is a calculation done by the test machine and is at tailpipe so after the cat.

It is not possible to use the calculated lambda to say unequivocally that the engine fuel air mix is correct.
 
koalar said:
you done the same as me


the fast idle has also failed just doesn't have a circle around it


lambda is Bob on. mixture is correct. So CAT isn't doing its job. Clogged or not hot enough
Click to expand...
The exhaust calculated lambda cannot be used to say mixture is correct.

It is correct at fast idle though at the very limit that the ecu can reduce mixture.

The mixture at idle is far too rich , high co at tail pipe after the cat proves case(even without a cat if engine was able to enter closed loop and control fuel mixture the co could not reach 8%)
 
jackwhoo said:
The exhaust calculated lambda cannot be used to say mixture is correct.

It is correct at fast idle though at the very limit that the ecu can reduce mixture.

The mixture at idle is far too rich , high co at tail pipe after the cat proves case(even without a cat if engine was able to enter closed loop and control fuel mixture the co could not reach 8%)
Click to expand...

I don't know about 8%

see post above 5% needed no new parts fitted

HC aren't High.

I would talk to a local garage and get them to do an emissions test for me straight after a proper run.
 
DaveMcT said:
Do you have an IR thermometer? The catalyst burns excess HCs. The outlet should be hotter than the inlet. If it's the same, the cat isn't working.

Wikipedia says -
Damage
Catalyst poisoning occurs when the catalytic converter is exposed to exhaust containing substances that coat the working surfaces, so that they cannot contact and react with the exhaust. The most notable contaminant is lead, so vehicles equipped with catalytic converters can run only on unleaded fuel. Other common catalyst poisons include sulfur, manganese (originating primarily from the gasoline additive MMT), and silicon, which can enter the exhaust stream if the engine has a leak that allows coolant into the combustion chamber. Phosphorus is another catalyst contaminant. Although phosphorus is no longer used in gasoline, it (and zinc, another low-level catalyst contaminant) was until recently widely used in engine oil antiwear additives such as zinc dithiophosphate (ZDDP). Beginning in 2004, a limit of phosphorus concentration in engine oils was adopted in the API SM and ILSAC GF-4 specifications.
Depending on the contaminant, catalyst poisoning can sometimes be reversed by running the engine under a very heavy load for an extended period of time. The increased exhaust temperature can sometimes vaporize or sublime the contaminant, removing it from the catalytic surface. However, removal of lead deposits in this manner is usually not possible because of lead's high boiling point.
Any condition that causes abnormally high levels of unburned hydrocarbons—raw or partially burnt fuel—to reach the converter will tend to significantly elevate its temperature, bringing the risk of a meltdown of the substrate and resultant catalytic deactivation and severe exhaust restriction. Usually the upstream components of the exhaust system (manifold/header assembly and associated clamps susceptible to rust/corrosion and/or fatigue e.g. the exhaust manifold splintering after repeated heat cycling), ignition system e.g. coil packs and/or primary ignition components (e.g. distributor cap, wires, ignition coil and spark plugs) and/or damaged fuel system components (fuel injectors, fuel pressure regulator, and associated sensors) - since 2006 ethanol has been used frequently with fuel blends where fuel system components which are not ethanol compatible can damage a catalytic converter - this also includes using a thicker oil viscosity not recommended by the manufacturer (especially with ZDDP content - this includes "high mileage" blends regardless if its conventional or synthetic oil), oil and/or coolant leaks (e.g. blown head gasket inclusive of engine overheating). Vehicles equipped with OBD-II diagnostic systems are designed to alert the driver to a misfire condition by means of illuminating the "check engine" light on the dashboard, or flashing it if the current misfire conditions are severe enough to potentially damage the catalytic converter.
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At idle the ops o2 sensor is pegged at 0.9v
Long term fuel trim -100

This suggests to me an excess fuel condition at idle rather than a faulty cat.

At fast idle the mot emission test is a pass.
 
koalar said:
I don't know about 8%

see post above 5% needed no new parts fitted

HC aren't High.

I would talk to a local garage and get them to do an emissions test for me straight after a proper run.
Click to expand...
Your suggestion would not fix the underlying issue of excess fueling at idle.

The cat is working as it can clean up the fast idle emmisions even though it appears the ecu fast idle fuel trim is also at its maximum lean limit.

I did see you posts about emmisions of a different car , you are lucky to have a friendly garage that could redo emmisions test ok :) that was a dramatic change in co over 5% to 0.06%

I had a car that failed twice at 0.4 co
Had to put a new car on it, then passed
0.01 co. The cat was completely dead and co was still low just not low enough to pass mot.
 
Last edited:
recap I had missed some posts


"I have changed the lambda and MAF pressure /temp sensors to no avail"

"RPM 735"

"non fluctuating steady bank1 lambda voltage at idle, but fluctuating at fast idle."

"Obd2 live data readings when first start car.
As can be seen TP(throttle position) =0% and 1st stage lambda (02) =9v non fluctuating"

"After a few mins and TP at 8.6% & fast idle the 02 sensor is fluctuating between 0.04 and 0.8v.
However as soon as I remove pressure on the accelerator back to steady 0.94v"


"Short term fuel trim reading at idle mainly at -100% and every 40secs or so increasing to -60-70 for a couple of secs and back to -100 at idle at fast idle goes up to 0% and slowly levels out if held steady at a % relevant to throttle position
Long term fuel trim is -100 at idle and does not change at all. Then at fast idle will change for a fraction of a second but returns to -100 immediately and stays there no matter what throttle position is."

What a mess

why hasn't the trim values thrown up an engine running rich code ?

735 RPM sounds a touch low ?
 
At work so can't do much today, but forgot to mention that when I remove the MAF air/pressure temp sensor and put my finger over the hole the 02 emissions halve to 4 hence why I changed the sensor.
 
Ricardogalpini said:
At work so can't do much today, but forgot to mention that when I remove the MAF air/pressure temp sensor and put my finger over the hole the 02 emissions halve to 4 hence why I changed the sensor.
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Unfortunately that doesn't give any useful information.
 
try disconnect. the purge valves electrical connector. Blue pipe at the back of the throttle body.

any way to do a compression test ?

don't understand how the long term trim isn't setting a P0172 code should do.


Don't think it will help if you disconnect the battery the ECU will reset and relearn.
 
My mate is bringing me a spark plugs socket that should fit tomorrow, so will take out plugs and post pictures. I have also ordered a 2nd hand throttle body.
 
Ricardogalpini said:
My mate is bringing me a spark plugs socket that should fit tomorrow, so will take out plugs and post pictures. I have also ordered a 2nd hand throttle body.
Click to expand...
Too much fuel is going in cylinders even though the ecu has reduced the fuel as low as it can, extra fuel is still going in.
That fuel has to be coming from somewhere.
 
1st plug out, looks good
 

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Again no oily deposit just grey and brown
 

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