Tuning Complications

[NFS]

I recently decided to install the throttle body of a Polo GTI into my 1.4 16V polo (2001). Everything fits and works perfect, all bolts match and the buterfly valve opens correctly. However the car revs now jump with only one fault code appearing -

17961 - Barometeric / Manifold air pressure: implausible correlation

I have checked for any air leaks but nothing what-so-ever. Error seems to come up due to too much air entering?

Can sum1 please tell me how i can solve this problem.

Cheers

 

[Prince]

Not really too sure of this myself. I'm sure one of the others will be along soon to advise you. Have you changed the air filter? Do you have a CAI?

Welcome to the forum btw!

 

[NFS]

Thanks for the quick reply. Air filters clean...everythings perfect, because when i put the original throttle body back on it work perfectly.

 

[Prince]

I copied and pasted the fault code into google and hit search. I found this: http://www.seatcupra.net/forums/showthread.php?t=202070&page=2

Read from page 22 mate.

 

[NFS]

Dont think my problem is the same, as when i put the original throttle body back on everything works as normal.

 

[MasterAuron]

The change in airflow may well be too much for the ECU to account for. IE outside its parameters.

 

[NFS]

The change in airflow may well be too much for the ECU to account for. IE outside its parameters.

Do you think a remap can change this? Or can anything else be done to make it work?

 

[Prince]

Do you have an air intake fitted?

 

[NFS]

You mean the inlet manifold? The original one and the GTI one were both used and the same problem. If you mean the air filter i didnt connect it (incase i had to take everything off the put the orginal back on).

 

[HDi fun]

Is the sensor simply faulty or badly connected and giving spurious output?

 

[lutonmatt]

The change in airflow may well be too much for the ECU to account for. IE outside its parameters.

what he said lol
the gti one is out side the 1.4's parameters so will throw up the fault every time
might be able to take it to a garage and they might be able to rest the air flow sensor i have done it a few times but on vauxhalls
is a common thing when you change them you have to reset the parameters

if it can not be done at a garage will have to take it in vw they can do it

 

[NFS]

what he said lol
the gti one is out side the 1.4's parameters so will throw up the fault every time
might be able to take it to a garage and they might be able to rest the air flow sensor i have done it a few times but on vauxhalls
is a common thing when you change them you have to reset the parameters

if it can not be done at a garage will have to take it in vw they can do it

Can it be reset through a Vag Com? Also by resetting the air flow sensor would it just simply put it back to its orginal settings or change them to compensate for the increased air flow?

 

[pgarner]

Dont think it can mate, havnt looked far into VAGCOM but theres only certain parts you can change. then again im using the older 409.1 version

 

[obi_waynne]

It sounds like the air flow sensor is sending much higher figures through to the ECU than the ECU expects. Swapping out the whole loom and ECU is probably the only way you'll fix it or merging the throttle body air flow meter with the original air flow meter.

 

[Sid447]

Can I ask the OP,

Why do you feel fitting a bigger TB will give you an advantage?

Modern cars are set-up by the manufacturers who spend millions on research and development to validate production cars with the best balance of parts to suit all conditions anywhere on the planet.
Simply bolting on a part that's bigger doesn't mean it's better. That's a fact.

In most cases fitting a bigger TB to an OBD-II car will send the air density signal to the PCM out of limits.

If you have access to the specialist equipment you can try re-tuning the maf-sensor with a different maf-calibration, or try fitting the same maf-sensor from the type of car you got the TB from but you will probably find that you will have lost power as the TB fitted to the 1.4 is no doubt optimal for that engine capacity as mentioned in the first paragraph.

Fitting a TB that is bigger generally just slows down the gas speed going into the engine cylinders and will cost you slower throttle response (power) at lower and mid-rpm and MAY if tuned correctly give you a slack handful of hp right at the top of the rpm range.
Which is basically what fitting bigger TB's to any engine will do unless a particular engine is seriously strangled in the first place, which is very unlikely nowadays.

Give VW some credit! They know what they are doing most of the time.
You would be well advised to re-fit the validated and proven part back on and look at a more practical way of gaining power if that's what you are after.