General To high Co readings.

[Migaard]

Hi.

My Marea 1,6 16V was at the danish version of MOT test a week ago.
Everything was OK, except the Co readings at idle was way to high...
The car idles OK, maybe a bit to low (600-700rpm) but when the car returns to idle from high rpm's it drops to 400rpm (nearly stalls) for a split second and then returns to 600-700rpm.

Anybody got a clue?

 

[Hellcat]

Worn out catalytic convertor?

Worth dumping a bottle of injector cleaner into a nearly empty fuel tank and then give it a thrash up and down the quick roads to clean the engine out.

Make sure the engine is hot at the time of the MOT otherwise the catalytic convertor won't be working correctly.

 

[bulldog5046]

a full bottle into an almost empty tank? isnt that a bad idea?

 

[Hellcat]

Maximum cleaning effect?

Spraying carb cleaner direct into the butterfly valve worked a treat on the Sedici.

On diesels they reccomend pouring the whole bottle into the diesel filter.. not so easy to do on a petrol.

 

[bulldog5046]

on the bottle it says to add the full bottle to a full tank on petrol

 

[Migaard]

Hi Guys.

The motor was warm after a fresh ride.
The Co reading was only to high in idle, when he increased the revs the readings were OK.
He states that when the Co is OK at higher revs the CAT + Lambda sensor is working and there's something wrong with the idle control.
(Had my ISCV tested OK a months ago).
I'll try to give the injector cleaner a go.

 

[Hellcat]

Does it idle ok? No hunting?

 

[Renegade_8]

Someone else i know had a fail with a Toyota Previa (it's alright, she is aa married woman hahaha) for this and a change of spark plugs and HT leads cured it. I would never have thought that myself. I would change the air filter and the oil as well.

 

[Migaard]

Thanks for the info.
The Ignition coil, HT cables and spark plugs are 3 months old, so they are OK.
I had the car at a garage today, it turned out to be the Lambda sensor that was out of range, causing the idle to be very low and the Co reading to high.
The Co was OK at high revs and that confused me.
The the sensor was working, but not at the right specs.

So now the car can pass the MOT test