my 2001 octavia has been spluttering and missing its worse when its cold also the engine wont rev very high ;

changed plugs and ht leads but it makes no difference any ideas what the problem is

What engine is it? Could be coil pack(s) that have failed?

its a 2.0l petrol code aqy

I'd go for coil packs first, then MAF maybe. + Throttle body clean.

I'd think try the MAF test first (disconnect MAF and see if engine runs better on the default air map [cos it's a free test]) then coil pack(s).

sorry but i"m no mechanic.what is maf?thanks in advance

MAF = Mass airflow meter its located in top right as your looking at the car.

Picture - http://www.oneighturbo.com/docs/MAF_cleaning1.jpg

IF the MAF test is inconclusive do a search for "vag com map" to see who is near you. were such a helpful bunch :-)

thanks to all but all this is going over my head,could anyone explain what the maf is exactly and how to find it and disconnect it,also what is a vag com search,sorry but my car knowledge is limited compared to yourselves.thanks again

also forgot to mention my car is not a turbo

MAF is the Mass Airflow Meter, measures the amount of air flowing into the intake (turbo or non turbo) based on the readings that the MAF reports to the ECU(the Engine control Unit) the ECU then decides how much fuel etc should be going into the engine. if the MAF is faulty then car can over or under fuel. the simple test that Ken mentioned is Really Simple. pipe that comes out the side of the air filter box has a plastic bit attached before another bit of pipe, coming off that plastic bit is a cable. engine off ignition off and remove the cable(some spring clips). try running the car and see if it makes a difference - reason it might is that with the MAF disconnected the ECU has no signal about the air flow so uses approximation data that the factory worked out should work OKish in most countries. so if it runs better you have confirmed the MAF as faulty or in need of a clean.

VAG COM is a bit of software that users with cables can use to connect to your cars various electronic bits via the diagnostic port under the steering wheel. in this case to read the fault codes from the ECU(helps with diagnosing a problem) HTH

Still see post 4.

The MAF is after the air intake box (where the air filter is situated) assuming you haven't replaced it, (I doubt this judging by your previous posts).

As said VAG Com is a computer programme that can tell you what fault codes your car has thrown up & thererfore how to repair your car.(theoretically:rolleyes:)

There's a good chance the exhaust may be blocked, especially if you've been driving with a misfire. Loosen the frontpipe bolts and drive it up the road. Beware that it will sound like a racing car, but if the power is restored to normal you know the exhaust, or most likely the catalyst is blocked.......

Thanks for the replies:) it is a problem with MAF,at first i didnt cover hole where i removed MAF,seems to be running fine:my question now is do i need to replace it?is the MAF important?if i need too replace MAF how much are they and any tips on suppliers.thanks again for all your help

Thanks for the replies:) it is a problem with MAF,at first i didnt cover hole where i removed MAF,seems to be running fine:my question now is do i need to replace it?is the MAF important?if i need too replace MAF how much are they and any tips on suppliers.thanks again for all your help

The Mass Air Flow sensor is important. It's what tells the ECM the load the engine is under, and is the most critical part of the engine management system, except for perhaps the engine speed sensor. You would not be able to do away with it, or bypass it. If you did the engine could only run in 'limp home' mode, with the ECM using predetermined values......

it seems fine and is running great,most definately not limping home,does anyone know price of MAF for 2.0L 2001 octavia

it seems fine and is running great,most definately not limping home,does anyone know price of MAF for 2.0L 2001 octavia

Limp home is the name for the state the ECM is in when it cannot receive information from a particular part of the system. The MIL lamp will usually be on at this time. It doesn't mean that your car is literally limping home, nor does it necessarily mean you'll notice any serious reduction in performance.

Why does the car have all these sensors if the ECM can run without them you may ask? That's a question I've often asked myself, and I suppose one day ECMs will be completely pre-programmed. For now though the ECM has to be continually informed of all the variables......

Thanks for the replies:) it is a problem with MAF,at first i didnt cover hole where i removed MAF,seems to be running fine:my question now is do i need to replace it?is the MAF important?if i need too replace MAF how much are they and any tips on suppliers.thanks again for all your help

Got mine from GSF cost about £90.00 but you get around £30.00 back if you take your old MAF in as trade in.

Iirc they did do a cheaper one as well but not a recognised brand, so it's up to you which one you want.

does anyone know if there are other models which use the same MAF as a skoda octavia 2.0 L petrol 2001? are there VW or seat compatible MAF"s ?

I'd guess at any other VAG car using a full EMS and the 2.0l 8v engine having the same MAF.

On the general points, when you're testing a possible MAF failure, you disconnect the electrical plug, not remove the MAF!!!

As for why you have all these sensors, they carry out diagnostics, and choose "near optimum" settings for actual conditions. They're what makes it possible for a modern EMS engine to pick up from near idle speed in most or all gears, and allow productive remaps to offer 20 to 30% more power!

thanks for all replies,i removed MAF sensor and car runs as well as it ever has.there's still something that bothers me;not long ago i heard a beeping noise under the bonnet,ignored it at first but after a while i found that it's coming from the Evaporative loss emission control system.could this be at the root of problems with MAF?i repeat that it beeped with MAF connected and after i removed it,also the car still ran poorly after unplugging MAF but when i removed the sensor and covered the hole it runs perfectly.can anyone shed light on these problems because my car knowledge is not great.cheers