There was a snow storm where i live in march and my car after that has lost i would say 40% in power. it is a skoda octavia 2003 petrol engine 2.0 liters 5 spd manual.

I have checked the codes and it has no faults, the CAI has no problems, i have had it serviced, oil and exc.

It is slow in rev, maybe 15 % loss in power, but when i go over 3800 rpm it is slow . there is no change in power when i change from 5. to 3. gear onlu more rev noise. and in 5500 the engine soounds like it is geting to the rev limit. but if i drive slowly and build up speed the then i can take it too the red rev limit.

.and the fuel consumption is to much maybe 12-18 liters per 100 km

im not driving the car like a maniac but i would like to be able to overtake some cars occasionally.

I have taken it to a autogarage but they couldn find any thing wrong

If somebody can tell me what is wrong then i would be very happy

MAF maybe? I am not that good with petrol engines though. I assume you can do the same as with the diesel and unplug the MAF and go for a drive, and if the car performs better you might have found your issue. Otherwise maybe the Coolant Temperature sensor?

Sure a more knowledgeable petrol person will be along soon :-)

MAF maybe? I am not that good with petrol engines though. I assume you can do the same as with the diesel and unplug the MAF and go for a drive, and if the car performs better you might have found your issue. Otherwise maybe the Coolant Temperature sensor?

Sure a more knowledgeable petrol person will be along soon :-)

It's not the MAF tried that, where is the CTS sensor located

It's not the MAF tried that, where is the CTS sensor located

I would have thought it was the MAF.

When you say you tried it, do you mean the engine ran even worse when it was disconnected?

I would have thought it was the MAF.

When you say you tried it, do you mean the engine ran even worse when it was disconnected?

Yes it ran worse and some warning lights came on in the dashboard

If it would be the MAF shouldn't be seen on the code computer

Edited 9 May, 201016 yr by Morte

Yes it ran worse and some warning lights came on in the dashboard

If it would be the MAF shouldn't be seen on the code computer

No One, could this be the catalystic converter

Could be a blocked cat but then I'd expect you'd get a code and a light come on as the readings between the lambda sensors before and after the cat would be all wrong. The only way you'd know for sure would be to get the exhaust taken off and have a look.

Your mpg sounds very low, 100km out of 12-18 litres works out as between 16 and 24 miles per gallon and a 2 litre petrol should get well above 30 mpg.

Edited 11 May, 201016 yr by chicken_eyebrow

Could be a blocked cat but then I'd expect you'd get a code and a light come on as the readings between the lambda sensors before and after the cat would be all wrong. The only way you'd know for sure would be to get the exhaust taken off and have a look.

Your mpg sounds very low, 100km out of 12-18 litres works out as between 16 and 24 miles per gallon and a 2 litre petrol should get well above 30 mpg.

it used to go 42 mpg before the snowstorm (if my wife was driving) will give it a try and let u know

it used to go 42 mpg before the snowstorm (if my wife was driving) will give it a try and let u know

Now i have changed the Maf sensor , sparkplugs and wires. checked all hoses, fuel filter but it is still the same, What can it be , can it be the throttlebody i'm getting really frustrated and broke, does anybody have any idea

Have you checked or changed the coolant temperature sensor?

Another thing to check is the exhaust is ok and not broken or leaking anywhere as that will make your fuel consumption go up a lot

I'd change the CTS with a genuine VAG one, & see if it helps. If you have climate control there is a way of using it to display what the ECU is seeing from the CTS. If the ECU is getting an incorrect reading from the CTS it can cause all sorts of running problems.

IIRC you press fan down, cold (blue) and ECON at the same time to put the climate control into the mode where you can see what the sensors are reading then press ECON again to come out of it. You can scroll through the sensors using the temp down/up buttons. There was a post on an Audi forum somewhere that listed what sensor each block refers to.

Edited 6 August, 201015 yr by chicken_eyebrow

IIRC you press fan down, cold (blue) and ECON at the same time to put the climate control into the mode where you can see what the sensors are reading then press ECON again to come out of it. You can scroll through the sensors using the temp down/up buttons. There was a post on an Audi forum somewhere that listed what sensor each block refers to.

I dont have climate control and when i removed the exhaust there was no change, i'm gona try the CTS. but there are no error codes in the computer

IIRC you press fan down, cold (blue) and ECON at the same time to put the climate control into the mode where you can see what the sensors are reading then press ECON again to come out of it. You can scroll through the sensors using the temp down/up buttons. There was a post on an Audi forum somewhere that listed what sensor each block refers to.

CTS is channel 51

I dont have climate control and when i removed the exhaust there was no change, i'm gona try the CTS. but there are no error codes in the computer

Pretty sure that a CTS fault doesn't usually throw a code unless it's gone open circuit.

Pretty sure that a CTS fault doesn't usually throw a code unless it's gone open circuit.

Ok will try that thanks

Ok will try that thanks

I ghanged the CTS but still no change :(

Had a friend with a 2 litre Golf GTi, AQY engine code (I think), his fuel consumption dramatically increased. There were no fault codes, so I took a guess at the first lambda probe, a bit of a gamble at £100, but replacing it sorted it out.

The reasoning being that if the fuel consumption is high then it is over fuelling, which will lead to decreased performance as there will not be enough air for efficient combustion. The MAF and CTS all check out and the only other sensor that has a large effect on fuelling is the lambda. If the car has two lambda sensors, the second one downstream of the cat is usually there for cat monitoring purposes, which leaves the first one as the problem.

The timebelt had gone wrong 3 teeths. But now it is maybe got 75% power back and still they cant find whats wrong. know the rev go to 4800 rpm before it goes power less. and when the car is cold it is jurky and there is maybe 50% power . Arg started to hate this car.

if the cambelt had jumped 3 teeth would this not cause some valve damage? dont how close the valve are to the pistons on these. get a compression test done in case.

Edited 16 September, 201015 yr by Clarkyzs