HI Hope some one can help me...
I had my Punto 55 1.1 (1997) to the MOT twice both times failing due to high CO exhaust emission Also I can se Lamda is "pass" Even though is to slightly to high ?


The first test 27/02/05

Fast idle Test: Target:

rpm: 2775 2500-3000rpm PASS
CO: 0.548% <=0.300% FAIL
HC: 31ppm <=200ppm PASS
Lambda: 1.032 0.970-1.030 PASS


Second Fast Idle Test:

rpm: 2604 2500-3000rpm PASS
CO: 0.706% <=0.300% FAIL
HC: 26ppm <=200ppm PASS
Lambda: 1.030 0.970-1.030 PASS


Natural Idle Test:

875rpm 450-1500 PASS
0.492% <=0.500% PASS

I have then changed the Air filter and spark plugs which were quite filthy but as you can see it actually made the CO slightly higher...

I also toke the car for a "high rev" 45 min drive to the MOT center but no difference... :bang:

Second Test 09/03/05

Fast idle Test: Target:

rpm: 2650 2500-3000rpm PASS
CO: 0.772% <=0.300% FAIL
HC: 41ppm <=200ppm PASS
Lambda: 1.037 0.970-1.030 PASS


Second Fast Idle Test:

rpm: 2807 2500-3000rpm PASS
CO: 0.704% <=0.300% FAIL
HC: 28ppm <=200ppm PASS
Lambda: 1.030 0.970-1.030 PASS


Natural Idle Test:

846rpm 450-1500 PASS
0.539% <=0.500% FAIL

Kwick-fit then adviced me to change the back box for £122 because it was ratteling (apparently) and it would help to keep the pressure-? and lower the CO - but guess what...No change what so ever! :bang:

Now a Local garage have quoted me £70 for a two hour engine test..? plus approx £88 for two hours labour correcting the problem? of course VAT and parts are on top of that.
They were saying that it could be the temperature sensor?..maybe the lamda and last resort the ECU...make sence???


I am very novice when it comes engine magement systems...but what about the fuel incector ? if the spary pattern is all over the place this must clearly result in a poor fuel economy? - is this easy to check?

lots of questions..lots of answers - Hope you can help

the injector is easy enough to swap out, and yeah it could impact the emissions.

these are my emissions from my 1108cc Cinq (same engine as the punto55)





Everything was tried to sort them out. Standard airbox was brought back, ECU reverted back to standard map, new lambda sensor, new injector, thrashing the engine before testing.

Nothing worked, and i ended up sourcing a spare ECU (ta Gaz!) and trying it with that on. It went through first time.

right...

what i suggest you do, it put some optimax in the car... and take her out for a thrash. i mean it. or put some injector cleaner in your fuel.

not a nice thing to imply, however, thrashing the car will help clear out deposits in the Cat, which in theory has an effect on the CO2 emissons.

it does work, believe me. also check your lambda sensor, make sure thats working correctly.

give it a try. you really have to go for it, take it up the motorway, but be clearful, don't over do it.

j@mie said:

right...

what i suggest you do, it put some optimax in the car... and take her out for a thrash. i mean it. or put some injector cleaner in your fuel.

not a nice thing to imply, however, thrashing the car will help clear out deposits in the Cat, which in theory has an effect on the CO2 emissons.

Click to expand...

But the problem is co....not co2.....which basically means the fuel aint burning right (i dont know much about cars but i know my chemistry)

the amount of co2 cannot be altered, and is only an indication as to the amount of fuel being burnt, CO emissions however, should be minimal at all times, and high levels mean either the engine is overfuelling, or the air filter/pipes aren't working properly, as youve checked the airbox i would go with overfuelling

just a question but hows your mpg??

are you seeing the engine management light?

Thanks for your replys so far...

No I dont have any warning lights comming on and the car drives perfect...

I am not to sure about the MPG as i have not been driving the car a lot... but it must be using to much fuel...? right...? in order for the CO to be to high...


I can see "Arc" CO is Way higher than mine ..about 10 times !!! - how much did you have to pay for the "Diagnostic test" ? (not done at the MOT i suppose?)

Any one have a way af testing the CO before I take it to the MOT center for a retest... after takeing it up the motorway

have you tried a bottle of fuel injector cleaner and give it a good thrashing before the test?

No I have not tried to use a "fuel injector cleaner"
-is it easy to get hold of?
-I would then put it in the fueltank?

How harsh do I have to be with a good thrashing?

Would that really be able to bring emissoin down by 0.3-0.4% CO ?

go to your local fillign station and look for some stuff in a little bottle called "Redex". Make sure its the fuel injector version for maximum effect. It'll set you back about £3ish, but if it gets your motor through it's MOT, then it's certainly better than havign to spend a couple of hundred £££'s on a new car!

Trust me...the Redex stuff works a treat for me.....

Could this be the catalyst?

dont say that word!

I assume it could be but its quite low emission of CO but i guess it could be giving up slowly...

so to sum it up so far...

Buy Some "Optimax" take it for a TRASH! down the motorway for an hour

Buy a bottle of "Redex" (Make sure its the fuel injector version) take it for a TRASH! down the motorway for an hour


I Understand there is no "simple solution" and there is alot of sensors working (or not working )together...


let me see if I can get this right...

Any way to make sure my Fuel injector is working propperly...

Any way to make sure my lambda sensor is working...

Any way to make sure my Engine temp sensor is working...

Any way to make sure my Air Intake air temp is working...

Any way to check the CO prior to MOT...

The catalyst has three jobs:

Remove unburnt hydrocarbons - the combustion is never complete
Remove nitrogen oxides (NOx) and turn them back to Nitrogen and Oxygen - these are created due to the high temps in an engine.
And most importantly:

Remove CO - formed from not having enough oxygen to complete combustion. The cat should change this into carbon dioxide (goes to look at your CO2 output). Ah, they don't give it to you I don't know much about cars but I know about cats and the fact that would make me think it ISN'T dodgy is that your HC ppm result is very low.

I can see "Arc" CO is Way higher than mine ..about 10 times !!! - how much did you have to pay for the "Diagnostic test" ? (not done at the MOT i suppose?)

Click to expand...

For all the diagnostic work done on my car, and other done at MOT time (new driveshaft, new brake shoes, new h'brake cable.. and some other bits) I paid £60 in labour. I do like my local mechanic

For checking the sensors are working, check your yellow pages. There should be a place that'll specialise in the electronics side of cars. I took mine to one of these places (different fault a while ago, turned out to be blown HG), it cost me £25 to have the fault codes from the ECU read and also to have all the sensors checked at the same time.

ok bought the fuel injektor stuff...

put some in the tank..
drove for about an hour in 4th gear 75-85 MPH i guess i have to wait and see...

it just seems too easy...

(like a magic stain remover...never works does it...?)

I also got the petrol engine cleaner version which I will try to use.

Now i just need to test the CO ?

get the MOT station to just run an emissions test, save u doing the full MOT if the emissions will fail it again.

Mine had about 10 emission tests done!

just spoke to an "old" mechanic friend of mine..

told me to check my coolant level...

He thinks that if the coolant level is low the temperatur reading might be to low resulting in the ECU spraying more fuel into the engine..(like the good old "choke") to compensate for the more fuel used to start/run a cold engine...

could be a solution to the high CO problem...

Guess it should have bin the first thing I checked...

IT WAS VERY LOW !... well below the "MIN" line

Does that make sence and could it influence the ECU ?

Only really if the sensor has air past it and not water.

This might sound silly, but is your Punto one without a temperature gauge? Just thinking the thermostat might be stuck open and it's running too cold, hence the rich mixture.

Yes my punto do not have a temperature gauge just an "ohh my good my engine is on fire light" (which i have not seen)

is there two sensors one for the fan and one for the ECU ?

There's three sensors all in - a temp switch on the radiator to turn the fan on and off, a sensor on the passenger side of the intake manifold that tells the ecu how hot the coolant is, and a switch on the back of the head for the overheating warning light.

Does the heater get nice and hot when you're driving at steady speed - i.e. not stuck in traffic?

how clean is your air filter, that can makea big difference, i changed mine at hte weekend, it was filthy, yet it was last changed in october, i put it down to all the salt on the road in winter, a partially blocked air filter has a tendency to make an engine run rich, otherwise, it sounds like the dreaded cat is on its way out..........