Failed MOT on emisions
Discussion
I wonder if anyone can help I have a lovely low mileage 1993 Audi 80 2.3 and the car went in for the mot and failed on emissions.
The car doesn't use a drop of oil or water and runs lovely it also had a new cat and lambda sensor fitted a couple of years ago also there's not a whisp of smoke coming out the old girl.
I've been told by the garage that my emissions are double what they should be yet the car doesn't seem to run rich.
The garage said that it needs some cat cleaner and its currently getting some put in now by the garage, if it fails again I can't really afford to spend any more money on the old girl so wondered if anyone would have an idea what it could be.
The car doesn't use a drop of oil or water and runs lovely it also had a new cat and lambda sensor fitted a couple of years ago also there's not a whisp of smoke coming out the old girl.
I've been told by the garage that my emissions are double what they should be yet the car doesn't seem to run rich.
The garage said that it needs some cat cleaner and its currently getting some put in now by the garage, if it fails again I can't really afford to spend any more money on the old girl so wondered if anyone would have an idea what it could be.
Sorry about that.
These are the results but since the the results have come down due to the cat cleaner but still not enough. url]
|http://thumbsnap.com/EAabye4j[/url]
Sorry about the upside down pic.
Is there anyway to get them down further I've just had the oil changed since.
The actual failure states exhaust emissions carbon monoxide content after 2nd fast idle excessive
These are the results but since the the results have come down due to the cat cleaner but still not enough. url]
|http://thumbsnap.com/EAabye4j[/url]Sorry about the upside down pic.
Is there anyway to get them down further I've just had the oil changed since.
The actual failure states exhaust emissions carbon monoxide content after 2nd fast idle excessive
Edited by Vince70 on Wednesday 15th May 17:56
I think the garage owner is an idiot for suggesting a cat problem given how low those emissions are, and to suggest they are double....is a little misleading.
Lambda is slightly high which could indicate weak....although sounds more like a slight air leak in the exhaust to me.
CO suggests a little richer than it should be, but again marginal. This could again be down to a slight air leak.
Is the lambda sensor working correctly ?
Lambda is slightly high which could indicate weak....although sounds more like a slight air leak in the exhaust to me.
CO suggests a little richer than it should be, but again marginal. This could again be down to a slight air leak.
Is the lambda sensor working correctly ?
When you replaced the cat was it with a genuine one or one of the cheaper pattern ones? If the latter it could well be down to that.
Had a similar issue with a 306 a few years ago, with the pattern cat it passed the MOT just after being fitted but failed the following year. Fitting a genuine used cat (actually the same vehicle's original one which just needed a repair to the pipework) reduced the emission reading to virtually zero & an easy pass.
Had a long chat with the tester - who I've known for years - & he said this pattern cats issue is quite common.
Comparing the two the genuine was about twice the size of the pattern.
Had a similar issue with a 306 a few years ago, with the pattern cat it passed the MOT just after being fitted but failed the following year. Fitting a genuine used cat (actually the same vehicle's original one which just needed a repair to the pipework) reduced the emission reading to virtually zero & an easy pass.
Had a long chat with the tester - who I've known for years - & he said this pattern cats issue is quite common.
Comparing the two the genuine was about twice the size of the pattern.
stevieturbo said:
I think the garage owner is an idiot for suggesting a cat problem given how low those emissions are, and to suggest they are double....is a little misleading.
Lambda is slightly high which could indicate weak....although sounds more like a slight air leak in the exhaust to me.
CO suggests a little richer than it should be, but again marginal. This could again be down to a slight air leak.
Is the lambda sensor working correctly ?
Thanks Stevie for turning my photo round for me and putting my mind at rest. Lambda is slightly high which could indicate weak....although sounds more like a slight air leak in the exhaust to me.
CO suggests a little richer than it should be, but again marginal. This could again be down to a slight air leak.
Is the lambda sensor working correctly ?
I'm not the most mechanically minded but I'm going to have a look under the bonnet tomorrow or Friday to see what I can find.
paintman said:
When you replaced the cat was it with a genuine one or one of the cheaper pattern ones? If the latter it could well be down to that.
Had a similar issue with a 306 a few years ago, with the pattern cat it passed the MOT just after being fitted but failed the following year. Fitting a genuine used cat (actually the same vehicle's original one which just needed a repair to the pipework) reduced the emission reading to virtually zero & an easy pass.
Had a long chat with the tester - who I've known for years - & he said this pattern cats issue is quite common.
Comparing the two the genuine was about twice the size of the pattern.
I never had the cat fitted as it was done just before I bought the car so it was done only 4000 miles ago but getting an audi one for my car is nigh impossible as the car is quite old now. Had a similar issue with a 306 a few years ago, with the pattern cat it passed the MOT just after being fitted but failed the following year. Fitting a genuine used cat (actually the same vehicle's original one which just needed a repair to the pipework) reduced the emission reading to virtually zero & an easy pass.
Had a long chat with the tester - who I've known for years - & he said this pattern cats issue is quite common.
Comparing the two the genuine was about twice the size of the pattern.
I hope it's not because its a pattern one
paintman said:
When you replaced the cat was it with a genuine one or one of the cheaper pattern ones? If the latter it could well be down to that.
Had a similar issue with a 306 a few years ago, with the pattern cat it passed the MOT just after being fitted but failed the following year. Fitting a genuine used cat (actually the same vehicle's original one which just needed a repair to the pipework) reduced the emission reading to virtually zero & an easy pass.
Had a long chat with the tester - who I've known for years - & he said this pattern cats issue is quite common.
Comparing the two the genuine was about twice the size of the pattern.
Exactly what I was about to say. Even with the type approval laws on cats the cheap ones will rarely make it a year to another mot. That's why they cost £50/60 and genuine cats are hundreds. Had a similar issue with a 306 a few years ago, with the pattern cat it passed the MOT just after being fitted but failed the following year. Fitting a genuine used cat (actually the same vehicle's original one which just needed a repair to the pipework) reduced the emission reading to virtually zero & an easy pass.
Had a long chat with the tester - who I've known for years - & he said this pattern cats issue is quite common.
Comparing the two the genuine was about twice the size of the pattern.
I hope it's not because its the cat.
It's a shame the car is not a year older as if it was a 92 I guess it wouldn't need a cat and I could have got away with a decat pipe.
My other car is 18 years old and still on the original cat and exhaust and my father just got rid of his A6 which was 19 years old and still on the original one and both have sailed through the mot recently.
I guess it's a case of cheap Chinese pattern parts.
But I'm going to have a look for any leaks as suggested by Steve and take out and clean up the plugs and air filter and give her a tenners worth of super and an Italian tuneup.
And keep my fingers and toes crossed.
It's a shame the car is not a year older as if it was a 92 I guess it wouldn't need a cat and I could have got away with a decat pipe.
My other car is 18 years old and still on the original cat and exhaust and my father just got rid of his A6 which was 19 years old and still on the original one and both have sailed through the mot recently.
I guess it's a case of cheap Chinese pattern parts.
But I'm going to have a look for any leaks as suggested by Steve and take out and clean up the plugs and air filter and give her a tenners worth of super and an Italian tuneup.
And keep my fingers and toes crossed.
Just taken the first plug out and it looks like this. 
Going to give them a clean it does look like steve is right as the plug looks like its been running lean.
The picture didnt come out too well but the tip of the plug is a white colour
I couldn't get the air filter out without ripping it so a thought I better leave well alone.
I've never seen an air filter like it it seems that half the injection system has to come out to get to it either that or you need two pair of hands lol.
Also the rotor arm could do with renewing as its quite worn I've just cleaned it up with a bit of fine wet and dry for now.
I will give it a run for about half hour before it goes in again.
Going to give them a clean it does look like steve is right as the plug looks like its been running lean.
The picture didnt come out too well but the tip of the plug is a white colour
I couldn't get the air filter out without ripping it so a thought I better leave well alone.
I've never seen an air filter like it it seems that half the injection system has to come out to get to it either that or you need two pair of hands lol.
Also the rotor arm could do with renewing as its quite worn I've just cleaned it up with a bit of fine wet and dry for now.
I will give it a run for about half hour before it goes in again.
Edited by Vince70 on Thursday 16th May 12:17
You're barking up the wrong tree with plugs and cleaning unless one has actually stopped working properly which would be quite obvious.
It could well be a clogged up MAF sensor, throttle or idle valve, I would either take it to someone who knows what they are doing (Independent Audi Specialist) or try an Audi specific forum.
It could well be a clogged up MAF sensor, throttle or idle valve, I would either take it to someone who knows what they are doing (Independent Audi Specialist) or try an Audi specific forum.
Edited by Evoluzione on Thursday 16th May 10:40
A few things that have helped me get cars through before in order of usefullness:
1. Give the car an oil/oil filter/air filter/spark plug/fuel filter change..... Not clean.
2. Ensure all engine breathers are clean & free from deposits.
3. Ensure there are ABSOLUTELY NO leaks in either the inlet, or more importantly the exhaust.
I don't think you have either a cat or lambda sensor issue if the car smells fine & runs smoothly.
FYI.
The only things that can cause excessive CO are:
1. Excessive combustible materials in the engine, ie. vapours from oil breathers, vapours from contaminated oil, vapours from the tank breathers.
2. Poor combustion fuel/air ratios, ie. low air flow.
3. Poor engine management control, ie. Lambda/cat/exhaust problems.
1. Give the car an oil/oil filter/air filter/spark plug/fuel filter change..... Not clean.
2. Ensure all engine breathers are clean & free from deposits.
3. Ensure there are ABSOLUTELY NO leaks in either the inlet, or more importantly the exhaust.
I don't think you have either a cat or lambda sensor issue if the car smells fine & runs smoothly.
FYI.
The only things that can cause excessive CO are:
1. Excessive combustible materials in the engine, ie. vapours from oil breathers, vapours from contaminated oil, vapours from the tank breathers.
2. Poor combustion fuel/air ratios, ie. low air flow.
3. Poor engine management control, ie. Lambda/cat/exhaust problems.
Edited by andyiley on Friday 17th May 13:18
Edited by andyiley on Friday 17th May 13:18
Hi the car has just come back from another mot at a different place after an Italian tuneup and it still failed.
But at least I didn't get a list of advisories as long as your arm this time.
But it does look like its because its a cheap Chinese cat that's fitted to the car that's caused the problem.
It's going to have to be another cheap one again as money is tight.
Anyone know where the cheapest place is for a cat fitted.
But at least I didn't get a list of advisories as long as your arm this time.
But it does look like its because its a cheap Chinese cat that's fitted to the car that's caused the problem.
It's going to have to be another cheap one again as money is tight.
Anyone know where the cheapest place is for a cat fitted.
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