Hiya guys,

A friend has jsut failed her MOT on emissions.

natural idle she passed fine, but failed twice on fast idle. Both failers were for CO and both times were over 0.60%

I've said I'll take a look at it for her but not being a toyota expert was wondering if any of you guys new where to start looking on this car? are there any KNOWN common faults with this car?

Oh it's a M reg carina e 1.8

As always any help / advise greatly appreciated.

guess the first thing to check is the Lamba sensor and that the air filter isn't clogged

I know it's not the air filter as that was only changed a couple of weeks ago.

It might be worth doing an oil change before you send it back.. if its burning a little oil, clean oil burns cleaner than dirty stuff.

Thats what I had to do with a Fiesta of that age.

also worth sticking a couple of gallons of super unleaded in too, which helps

was the engine up to temp when they checked?.

If it has a vane type air flow meter which several Toyotas of that age still had. Then there maybe a screw adjustment on it to change the idle mixture. I had this on my earlier Corolla and MR2 turbo.

carina e dont have the vane type air flow meter. as said cheque lambda sensor. also bit of fuel treatment and a good thrashing as some never get driven hard enough, i used to work in a toyota dealer and mot them. had plenty of old dears and gents with lazy lambda sensors. most got by with a good blasting up the road.

hope this helps

rob

I alays run the car low on fuel and then fill up with super unleaded and half a bottle of redex before an MOT

thats because you drive a jaguar!!!

i run a test centre and my advice would be book a re test and take the car out and thrash the cock off it just before you get there,when the chap hooks up the sniffer he will probably try to connect something to give the machine an engine speed which catted cars have to pass in the 2500-3200ish range .once its hooked up hold the car at 4500rpm and when the emmissions are in the green slowly lower the speed til the machine starts the test and you might get through, a tired cat will normally hover around 0.5 co and 80-100 ppm hc. we do 20-30 cars a day so we do this several times a day with older stuff ,its the cheapest option and 8 out of ten times it works but its also the easiest way to sell people emmissions services and magic potions

My Kia failed on the same reading as that and the garage told me to try some injector cleaner in a tank of fuel. It brought the reading down to 0.4% which was still not enough and I had to fit a new front cat pipe which did the job but cost £90.

Assuming the fast idle test is carried out at the correct speed --- ie at the top of the closed loop range.
I would go for a new lambda sensor, some injector cleaner and a good belting immediately before the test.

As already said the main problem with older vehicles is the lambda sensors get lazy, usual they don't actually stop working so don't flag up a fault code but they get slower to respond because of deposits and need to reach a higher temperature to work. Although you can test the lambda sensor considering the age of the vehicle the sensor must be pretty scanky by now.

There is an engine management warning light on on the dash (haven't been able to find anyone that can decode this yet though) M reg so not obd2 compatable.

Am currently thinking cat as the lambda readings on the test are both fine (although a little high) but as said the CO emmissions are over twice what they should be.

Also 2nd test was done at a slightly lower speed than the first, the HC level on the 2nd test were a fail but a pass on the first test.

Don't know if that sheds any more light?

As I said, I had the same problem, HC and Lambda were well in limits but CO was high. The cat box was almost empty when I took it off, absolutely fu**ed. With the new front pipe on it read 0.095 immediately and passed straight away. Converters are now fetching good prices as scrap and some thefts of them have been reported here They fetch £55 even in knackered condition.