Hello peeps, astra just failed MOT on emissions
Exhaust emissions carbon monoxide content at idle excessive - should be 0.5 and its 0.87
thats the only thing wrong, any ideas what cold be causing it
thanx
tony
the turbo
carb or injection?
i'm guessing injection. lambda sensor? cat?
Fast idle test
CO 0.26
HC 87ppm
Lamdba 1.00
Natural idle test
CO 0.87 - fail
?
1.6 8v 1600cc Single point injection
[Edited on 2/2/10 by t16turbotone]
I had somethingsimilar with my focus, nice garage chaps said try a fuel additive and thrash it for a tank full. Tried it and..... it was bit better
but still had to put a new cat on it Might be worth a try though?
Simple things first - grubby old air filter?
try plugs and air filter first...
Not that far out -
Could be few things, the lambda sensor could be sluggish or coolant temperature sensor on its way out or it could be the cat.
First thing to do is check the inlet manifold is tight and has no vacuum leaks, check the condition of the plugs and leads espeically checking the
plug gap.
The output from the lambda sensor really needs checked out, at idle the output voltage should jump between high and low at least a couple of times a
second. A new sensor responds a lot faster than one that has been in use for 80,000 miles. It is best to regard the service life of an upstream
Lambda sensor as 8 years.
Often a sluggish lambda sensor is often why it gets more difficult to get a car through the emmisions test as it gets older.
Best way to check the lambda output is to look at through the diagnostic port but a Digital Multimeter will also do the job.
The Coolant temperature sensor is also best checked out via the diagnostic port.
[Edited on 2/2/10 by britishtrident]
Mine was similar at sva,tried everything,putting off accepting it was the cat,unfortunately it turned out to be just that (supplied custom chrome)but
it could be any of the above,injector cleaner and a thrash first try!
Having said that, that was sva hitlers doing the test unable(or more to the point refusing to)do this perfectly legal 2nd test,my mot man (dad!)
managed to get it through on his machine using a different mode or something which allows longer time than the pre-set for your make model in the
analyser?Someone else can probably explain what I mean.Don't know if your guy tried this?
You could try something like Cataclean. Supposed to work well with kernackered cats.
give it a good thrashing
Thinking it over this a Vauxhall --- stuck EGR valve ?
One thing to be aware of if you have to buy a cat is that with a car built or used after 2001 having a Cat that is not type approved for that
particular model is an MOT failure.
In other words sports cats are an instant failure and cheap replacement cats are also a failure if the examiner decides to look at the the codes
stamped on the bottom of the cat .
quote:
Originally posted by britishtrident
Thinking it over this a Vauxhall --- stuck EGR valve ?
One thing to be aware of if you have to buy a cat is that with a car built or used after 2001 having a Cat that is not type approved for that particular model is an MOT failure.
In other words sports cats are an instant failure and cheap replacement cats are also a failure if the examiner decides to look at the the codes stamped on the bottom of the cat .
thanx for all your help guys
With an old 200,000+ miler diesel cavalier the mot prep went like this.
Good dose of injector cleaner
new air filter/ or remove it
block radiator off to get things nice & hot
thrash it to death beofre turning up for the test & dont let it tickover.
ie make sure the engine it as hot as you can get it.
if the tester is an arse go somewhere else, I fell out with kwikfit over this car years ago. Jumped up tester thought blocking the radiator off gave
him extra powers to try and fail the car.
second re test it was 0.005 inside the reading, he decided he wanted to do it again. I spent the next five minutes wiping him round the floor...
Find a decent "small" mot garage, use him to look after your car over the year and if he is ok stick with him.
Ive used the same garage for over 10 years, he knows me I know him.
Loyalty with a small garage can help when it comes to MOT time.
Its a bit like finding a good heating engineer, if you find one stick with him (or her)
quote:
Originally posted by SteveWalker
Looks like a good way to ensure that modern vehicles can never become classics - as you'll not be able to get the "approved" cats forever
I think BT was right, egr valve sticking, cleaned valve and retested, passed...
Using only fully synthetic oil helps prevent EGR valves sticking but for a longterm cure blank it off but leave the valve electrically connected --- that way no fault code is flagged.