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        General >> Problems >> How can I lower my CO for MOT?
        
(Message started by: carmow on Jan 7^th, 2008, 5:48pm)

Title: How can I lower my CO for MOT?
Post by carmow on Jan 7^th, 2008, 5:48pm

Can't believe it, the old girl has failed AGAIN on CO level, I made sure the engine was hot and even bought some of that 'so called' emission reducing additive. MOT runs out on 14th can anyone help... PLEASE !! :'(

Title: Re: How can I lower my CO for MOT?
Post by TiberiuS on Jan 7^th, 2008, 5:59pm

If you post the emissions results in full (CO, HC, Lambda etc), the levels of the different gasses sometimes point to different faults and someone can help.

Title: Re: How can I lower my CO for MOT?
Post by solarpanel on Jan 7^th, 2008, 6:15pm

is the cat broken

Title: Re: How can I lower my CO for MOT?
Post by carmow on Jan 7^th, 2008, 6:18pm

emission results as follows:

engine speed (RPM) 2750/3150
CO <=0.30 (actual 0.34) 2nd attemp (actual 0.38)
HC <=00200 (actual 00022) Passed
LAMBDA 0.95/1.09 (actual 1.00) Passed

Engine speed (RPM) 0775/0975
CO <=0.50 (actual 0.49) Passed

Its nearly there as you can see just not quite.

this is the retest result as it failed Christmas eve at 0.37 & 0.35

Title: Re: How can I lower my CO for MOT?
Post by carmow on Jan 7^th, 2008, 6:19pm

2nd reading was 0.38 - sorry

Title: Re: How can I lower my CO for MOT?
Post by TiberiuS on Jan 7^th, 2008, 6:36pm

Sounds like bad cat to me, I'd probably change the lambdas first but as the lambda is dead on 1.0, the mixture's ok...when my lambdas were dead, it was all the way up at lambda=1.3 and misfiring like a pig :o

Get it OBD scanned and see what the lambda reading is like.

this (http://www.petercoopercarrepairs.co.uk/new_page_3.htm) might help you.

Regards, Bruce.

Title: Re: How can I lower my CO for MOT?
Post by carmow on Jan 7^th, 2008, 6:56pm

Thanks for the link Bruce, just the mention of 'bad cat' makes me quake ! I bought the car 11 months ago for £325 at a local auction, i have before the test this year done both wishbones, drop links, front discs, bulbs etc is it worth throwing hundreds at it for a cat?
is their nothing I can do without getting the OBD read etc... time is against me!

Title: Re: How can I lower my CO for MOT?
Post by TiberiuS on Jan 7^th, 2008, 8:20pm

Maybe someone else has an opinion they can throw in, I'm not an expert, just what I've picked up from my own problems :)

As the lambda reading is ok, it doesn't seem like there's anything wrong with the mixture, HC is ok so it's not an engine/misfire issue (my HC was sky high along with the lambda, CO was virtually zero, car was spitting from the tailpipes when they had it on the fast idle).

Any other symptoms? Is it losing power/hesitating or running rough or anything else you've noticed? Lambdas will normally effect the running of the engine in some way when they die, either make it go lean or really rich, so you'll either start losing power or your mpg will go through the floor. Not every time but it's generally the sort of symptoms they produce. If the cat element is just dead through age, then it'll run ok, just like it would if you removed it. But it won't get through the MOT :-/. An OBD scan for fuel trims would be very handy, I'm not sure how much you can tell from the MOT lambda reading, OBD takes the reading directly from the oxygen sensors themselves.

You can read the lambdas yourself if you're careful and get at least some idea, with a voltmeter. There's a site somewhere that tells you how, I'll try and find it.

What's the total mileage and what's the mpg like?

Regards, Bruce.

Title: Re: How can I lower my CO for MOT?
Post by carmow on Jan 7^th, 2008, 8:25pm

Bruce, mileage is a very respectful 129K MPg is about 18 around town, 27 on a run. have just found a pipe off on the exhaust manifold, looks like a braided fuel pipe (obviously I know otherwise) goes to a small box behind air filter housing with an electrical connector on it, and then back into manifold - 2 pipes in total. any ideas? would this have anything to do with CO? thanks again Wayne

Title: Re: How can I lower my CO for MOT?
Post by mindofitsown on Jan 7^th, 2008, 9:19pm

Can only throw in an opinion which correlates with what has already been said by others namely: HC good thus virtually all fuel is being burnt so no misfires etc., Lambda is spot on thus O2 level is correct indicating mixture is good. CO high on its own does suggest the CO convertor (i.e. the cat) is in apoor state and if prematurely so, would suggest that someone in the past has had starting problems and flooded the cat with petrol which ruins the platignum catalyst. It also suggests that the EGR is working well unless being over-compensated for by computer. Its possible that the Lambda sensor is failing and giving the wrong signal to the computer and the over-compensation results in a mixture that gives the results you have shown, but I doubt it. The EGR system has some unpredicatable results including actually raising the level of CO under certain conditions. You might get away with dis-abling the EGR but as I say it may worsen things because of the interrelated nature of the variables in the system.

Title: Re: How can I lower my CO for MOT?
Post by Tons_of_fun on Jan 7^th, 2008, 9:50pm

Not saying it will work,but my old 2.0ltr was having similar problems with emissions,when the tester told me to remove the air filter from the housing whilst the car was being tested & it JUST scraped through :-/.You may be on to something with the disconected pipe though,sorry i cant be much more help.16 valvers arent my thing im afraid.Whatever you decide best of luck.

Title: Re: How can I lower my CO for MOT?
Post by Tompion on Jan 7^th, 2008, 9:51pm

on 01/07/08 at 20:25:25, carmow wrote:

have just found a pipe off on the exhaust manifold, looks like a braided fuel pipe (obviously I know otherwise) goes to a small box behind air filter housing with an electrical connector on it, and then back into manifold - 2 pipes in total. any ideas? would this have anything to do with CO? thanks again Wayne

Sounds like that's your problem - letting air in - may have been knocked off, but can get blown off due a blocked exhaust. Not normally braided hose so make sure it's a good fit.
Have a look here at the dpfe:
http://www.fordscorpio.co.uk/egrmonitor.htm

Title: Re: How can I lower my CO for MOT?
Post by scorpio_man on Jan 7^th, 2008, 9:55pm

hi there

does sound like the cat is breaking up. the pipe(s) that have come off the manifold/egr pipework have done so because of the pressure in the exhaust (cat). normally a sign of a blocked exhaust because of the cat brick breaking up.

new patterend cat costs about £90 + vat & delivery from cats direct.

hth

Title: Re: How can I lower my CO for MOT?
Post by carmow on Jan 7^th, 2008, 10:12pm

Sorry to sound dim, what next? Do I replace the cat and hope its that or try the car again with both pipes connected on the MOT machine ?
can't believe i did my apprenticeship at Ford 20+ years ago can you ! :P

Title: Re: How can I lower my CO for MOT?
Post by jonnycab on Jan 8^th, 2008, 1:09am

Hi carmow, 18 mpg around town is pretty poor for a 2.3 (I average about 23-24), so something isn't right somewhere ;)

I'd go with the cat theory, especially as the pipe has been blown off the manifold :)

Title: Re: How can I lower my CO for MOT?
Post by TiberiuS on Jan 8^th, 2008, 1:29am

Jonny. I used to average 24-25 on a run, 26 if I was a really good boy. MPG in town wasn't pretty, even worse after it had the new autobox :-/

Being able to score 30mpg in any car after that was a novelty ::)

Title: Re: How can I lower my CO for MOT?
Post by jonnycab on Jan 8^th, 2008, 1:50am

I run mine as a taxi & most of my work is around town driving. Do you think I'd keep my 2.3 if it only did 18 mpg around town :o

On a 180 mile run from Essex to Poole (family holiday) last June, I averaged just under 33 mpg ;)

What can I say ?.....I don't drive with deep sea divers boots on ;).....maybe I should change my forum name to Twinkle Toes ;D

Title: Re: How can I lower my CO for MOT?
Post by TiberiuS on Jan 8^th, 2008, 2:25am

Jonny, that post tickled me ;D

I think it's safe to say mine needed new lambdas ;)

I drive like a Nun too, at first I could manage 26 on a run, 22 in town. But after it was off road for the new autobox it was 'opeless.

33mpg though, I never saw anywhere near that :(

Must change my name, feel like a 'Nun on the run' now ::)

Title: Re: How can I lower my CO for MOT?
Post by carmow on Jan 8^th, 2008, 5:36pm

SUCCESS !!! ITS PAST !!
Speedo shows 18miles different from yesterday to todays test and it sailed through ! Happy days are here again.... Thanks to all who suggested help.

Title: Re: How can I lower my CO for MOT?
Post by TiberiuS on Jan 8^th, 2008, 6:12pm

What was the emission result on the latest test then? Did you do anything with the hoses?

Glad you're sorted though :)

Title: Re: How can I lower my CO for MOT?
Post by carmow on Jan 8^th, 2008, 8:14pm

emission results today:

CO 0.29%
HC 41ppm
lambda 1.01

natuaral idle test was 869rpm
Co 0.23%

all i did was push the hose back on that was off yesterday after the last test.

this time it went to an independant ford specialist and went straight through - amazing how the larger dealerships fail these lovely cars just because they don't like working on older models.

Title: Re: How can I lower my CO for MOT?
Post by TTPmaverick on Jan 8^th, 2008, 10:11pm

if your car is doing very little day after day it all ways helps a day or 2 before the M.O.T. to give it a good old thrashing can drop c.o. up to 1.0.
It gets the cat/cats up to a good temp and helps to get rid of nasty deposits

And with some customers its the only time the car gets a bit ;)

Title: Re: How can I lower my CO for MOT?
Post by a11mcr on Jan 8^th, 2008, 10:46pm

Hi jonnycab.How doyou get 23-24 mpg as my 2.3 estate struggles 15-17 round town (may have somthing to do with my other post HO2S ???).
Jammy g*t ;D
Mark

Title: Re: How can I lower my CO for MOT?
Post by Scorpio_Mike on Jan 8^th, 2008, 11:28pm

15 - 17 mpg from a 2.3 :o :o :o
Think you have a problem there - I get about 22 - 23 from my 2.3 estate on average, 30+ on a long run.
Used to get about 18 - 19 from my old 2.9 !

Title: Re: How can I lower my CO for MOT?
Post by Big_Green_Tank on Jan 11^th, 2008, 7:00pm

on 01/07/08 at 21:55:38, scorpio_man wrote:

This is what happened to my 2 Ltr and a new cat at that price cured it I was daft enough to secure said tube with a juilee clip and couldn't go above 50 Flat out!!!

Did they have Cats in many cars 20 Yrs ago I don't think so!
Don't worry mate your not as daft as you think you are LOL!!!

Bob

Title: Re: How can I lower my CO for MOT?
Post by mindofitsown on Jan 11^th, 2008, 8:39pm

Hi 'carmow', its a pity the second MOT was not done at the same garage because I would have like to have seen the figures for that. It would have been a true reflection of the difference from reconnecting the pipe. Instead, we have two variables to consider now: the true difference from the pipe fix and also the calibration tolerance between the two test machines which I've long believed is higher than most people suspect.

Title: Re: How can I lower my CO for MOT?
Post by carmow on Jan 11^th, 2008, 8:56pm

when the car past, it was a local Ford specialist, he tells me that if all the electrical items are turned on whilst doing the emissions test the engine has to work harder to power everything and so reduces the 'unburn' fuel in the system thus lowering the readings! does anyone else hold with this idea? ???

Title: Re: How can I lower my CO for MOT?
Post by solarpanel on Jan 11^th, 2008, 10:30pm

surely a reading of 0.29 it only just passed the test im sure it should be better than that?

Title: Re: How can I lower my CO for MOT?
Post by mindofitsown on Jan 15^th, 2008, 6:50pm

'Carmow' , I agree with 'solarpanel'. The CO reading should be about one tenth of what you have so there is still something not quite right. As for switching everything on to labour the engine, there is some truth in that in as much as it tends to reduce the HC level but that is not the problem its CO and by using this trick you may actually increase CO whilst reducing HC.

Title: Re: How can I lower my CO for MOT?
Post by harry.m1byt on Jan 15^th, 2008, 8:59pm

Carmow....

Your mpg seems quite poor even when compared to my 2.9 12v. Could it be the injectors causing the poor emmisions level and poor onsumption figures? Have a read of my car only just scraping through on its emissions its + poor mpg and how I seem to have fixed it.

The thread is here :- http://www.fordscorpio.co.uk/cgi-bin/yabb/YaBB.pl?board=Advice;action=display;num=1199535832