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Discussion Starter · #1 ·
My beloved Car today fail its MOT on Emissions and trying to think of what's wrong with it, as its the first time its failed here are the readings...

Fast Idle Test Limits Actual Value Result

CO <= 0.300% 0.667% FAIL

HC <= 200ppm 207ppm FAIL

Lamba 0.970-1.030 1.130 FAIL

Natural Idle Test

Engine Speed 450-1500 Rpm Manual Check PASS

CO <=0.500% 0.497% PASS

Things that i can only think of...

1. Rocker Cover gasket was leaking oil into one of the cylinders a while ago causing it to misfire and drink a bit more oil but it has had new plugs and has cured the problem but it maybe its still leaking into the cylinder? But it doesn't misfire at all run as normal.

2. Injecters may need cleaning? May bring down the CO emission as its so high, This has never been done while owning the car (2 Years)

3. It is due an Oil change next month but will that make a big difference? May help the HC emissions? It has got a new air filter and has had the TB cleaned.

4. A sensor of some sort not working correctly that i cant think of?

Your opinions and views on this would be great!

Thanks in advance!

Marco [Y]
 

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Discussion Starter · #3 ·
Thats what i was thinking of ages ago Chris but i don't think its the piston rings as my car isn't that bad for burning oil if the CO levels are so high isn't something to do with the Injection system or a bad Oxygen Lamba sensor ?

Marco [Y]
 

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As results show the lambda reading is on the high side, so I think for what it's worth it would be somewhere to start - especially if you have a lot of miles on the clock because the sensor is meant to be good for between 30 to 50k. Get a genuine Bosch one - cheap lambda sensors are a false economy because they don't last.

When was the TB cleaned? May be worth checking it out and cleaning again. With lots of short journeys these little petrols are prone to a lot of condensation building up in the air intake pipes, as well as a little oil. My 1.6 requires attention every few months to be fair [Y]
 

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Discussion Starter · #7 ·
As results show the lambda reading is on the high side, so I think for what it's worth it would be somewhere to start - especially if you have a lot of miles on the clock because the sensor is meant to be good for between 30 to 50k. Get a genuine Bosch one - cheap lambda sensors are a false economy because they don't last.

When was the TB cleaned? May be worth checking it out and cleaning again. With lots of short journeys these little petrols are prone to a lot of condensation building up in the air intake pipes, as well as a little oil. My 1.6 requires attention every few months to be fair
TB was cleaned about a month ago and it was covered in dirt all clean now, the car has done 102,000 and looking at the sensor it looks like its original

Marco [Y]
 

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Discussion Starter · #8 ·
Do you have a reading for the oil temperature from when those readings were taken? It almost looks like it wasn't warm enough
All i've got is this on the paper...

Description Limits Actual Value Results

Engine Oil Temp Min 60 Deg C -- Temperature Gauge

It is due an Oil change will that help?

Marco [Y]
 

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As results show the lambda reading is on the high side, so I think for what it's worth it would be somewhere to start - especially if you have a lot of miles on the clock because the sensor is meant to be good for between 30 to 50k. Get a genuine Bosch one - cheap lambda sensors are a false economy because they don't last.

When was the TB cleaned? May be worth checking it out and cleaning again. With lots of short journeys these little petrols are prone to a lot of condensation building up in the air intake pipes, as well as a little oil. My 1.6 requires attention every few months to be fair
TB was cleaned about a month ago and it was covered in dirt all clean now, the car has done 102,000 and looking at the sensor it looks like its original

Marco
[:S] That won't come out without a fight then! Mine was a job for the gas, and the thread in the manifold needed retapping.
 

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Discussion Starter · #10 ·
I Changed the CAT not so long ago and i had to change the first bit of the down pipe coming from the exhaust manifold, so that fight has already been and gone and i won! So shouldn't be a pain getting out. I think i will clean the injectors, Change the Lamba sensor and give it a oil change and see what happens its all i can think of, its just the CO level is way off it must be the sensor.

Cheers Fella

Marco [Y]
 

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Do you have a reading for the oil temperature from when those readings were taken? It almost looks like it wasn't warm enough
All i've got is this on the paper...

Description Limits Actual Value Results

Engine Oil Temp Min 60 Deg C -- Temperature Gauge

It is due an Oil change will that help?

Marco
So no reading for the temperature at all then, that's not very helpful.
 

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Discussion Starter · #12 ·
Do you have a reading for the oil temperature from when those readings were taken? It almost looks like it wasn't warm enough
All i've got is this on the paper...

Description Limits Actual Value Results

Engine Oil Temp Min 60 Deg C -- Temperature Gauge

It is due an Oil change will that help?

Marco
So no reading for the temperature at all then, that's not very helpful.
In short... No i'm guessing he has just looked at the temperature gauge, i took it for a quick run down a dual carriage way so the oil should have been warm enough, thanks for your reply

Marco [Y]
 

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Get some of that tramp fuel additive slap it in and drive the nuts off the car for 20 mins before you get it retested. Failing that think it maybe time for a new lambda.

All my tester does is when mine fails sticks the probe in another car.[whistle]
 

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Discussion Starter · #16 ·
All sorted now, just spoke to the man who does the MOT told him what i had done which was, changed the lambda sensor, oil changed and a injector cleaner, he just said ok wait there, and he came back with a nice green bit of paper so its now all sorted! Thanks for all your help gents!

Might pop into a garage near work and see wether all that actually has made a difference and the new sensor should help with the poor economy i've been getting.

Thanks again!

Marco
 
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