failed mot

[katentel]

it may come as no surprise to some of you but the sidewalk failed its mot today!!mostly minor stuff but did fail the emmisions and needs some welding.as i dont know much about the emissions i am in need of some advice..carbon monoxide readings after fast idle were .7 i believe the limit is .3 what is the cause of this? is it the cat or maybe the lambada sensor. shawn did a diagnostic check last week and it shows no faults. ideas please

[Miniböttcher]

i had the same thing on that bloody fiesta of julies son, i took the throttle body off , the bit with the butterfly, and gave it a good clean out, got rid of the built up where the butterfly sits at idle

when we did the exhaust and had the airbox off there was a bit of oil in there

a quick fix which dave told me about, get some carb cleaner, take the air box off, run the engine then rev it right up at the same time spraying the carb clean straight down the throttle body , it will start to struggle but will clear, it helps to clean all the inside the engine out and blow out all the crap, like i said its a quick fix.

did you ever get round to servicing that car, oil , oil filter, air filter, it may help alot, a dirty air filter will not help. and give you a bad reading.

[katentel]

Will try all that ta may need your help with the welding though

[gemma]

shawn said as there was no faults flaged on the diagnostics test he sugests u remove the air filter
failing that yes lamda sensor

[katentel]

thanks gemma

[Stephen]

What did it fail on- Lambda, hydrocarbons or CO? Often a hole in the exhaust system will affect Lambda as it sends the air to fuel ratio out the window. You can norrow the problem down just on the text results to suggest whether it's a problem with the cat or not.

If the lambda and hydrocarbons are within limits but the CO is out, this normally means the cat is nackered, as the air-fuel ratio is good so the ECU is not overfuelling due to a faulty sensor reading or hole in the exhaust. That only leaves the cat as not converting the gases properly.

[Stephen]

* i meant test results!

It won't necessarily show up on a fault reader if the cat is buggered

[Kris James]

i would more so suggest looking at the CAT

[monkeyjim]

Tel .

Need to be careful here as there could be all manner of reasons and you need proper advice away from the forum from people that really know about injection systems and diagnostics .

Check all basics are ok , water oil etc . Check vacuum hoses are in good condition . If Shawn has no fault codes that is a start . A minor exhausrt blow can also cause incorrect readings .

Sometimes they only need a good hard drive round the block to turn a emissions failure into a pass as a Rover 214 proved today .

If someone puts a post like yours on a forum , rightly or wrongly cats and ecu's are usually the first things to be suggested as the cause .

[katentel]

thanks dave havnt had a chance to lookat it properly yet but sounds good advice as it realy doesnt get out much a good blast may sort it out.will check out hoses etc do oil and air filter change. dean and i only put exhaust on 6weeks or so ago and pretty sure thats ok, however you cant really check cats and sensor can you? so i guess ill sort the other bits out and book a retest and see what happens

[monkeyjim]

There are test procedures to check probes using a multimeter on ohms setting . Cats can rattle or the internals break up causing them to block . Usually get loss of power when blocked , replaced one on a escort for that last week , was really flat and wouldnt go up hills .

Loads of helpful stuff on net telling you how to test componants . Got one of the inexperianced lads at work looking on youtube to find out how to check a throttle position sensor , he found it , tested it and replaced the faulty part curing the fault.

[Stephen]

Jul 26, 2010 20:44:48 GMT monkeyjim said:

Need to be careful here as there could be all manner of reasons and you need proper advice away from the forum from people that really know about injection systems and diagnostics .

Cos I know nothing bout SPi Minis me

The forum is a good place to start but don't take anything as gospel. I wouldn't waste my time posting here if I haven't got experience of what I'm helping with

[katentel]

ALL advice is greatly appreciated. at least it gives you pointers maybe not always in the right direction but at least it shows people are trying to help

[monkeyjim]

oh dear .
I did not say people do not know about a subject .

Although for example : Seeing as where I work there is over 100 years motor vehicle repair experiance between us , ex VAG and Vauxhall trained guys , a snap on diagnostic scanner , diagnostic fault code manuals , emmisions tester etc and daily experiance on modern cars there may well be people better qualified and equiped out in the field than others .

[MiniGT5]

A Simple fix would be to get a clockwork car

Where are Jim & Simon when you feel a good argument brewing

N