id like to start off by saying hello to everyone as i am new to this forum...

i drive a 1997 audi a4 1.8 20v that has done 105k miles, its in kingfisher blue.
the car is totally standard factory spec, apart from eibach lowering sport springs.

ive owned the car for approximately 6 weeks now and it is returning 10 miles to the gallon, i.e it is doing 35miles to a quarter tank of fuel...

i had the car fault codes read, which were,

throttle valve fault - ive been told to try cleaning first..i havent got round to doing this yet...

mixturer adaption above limit - i dont know what on earth this means....

temp sensor defect - ive replaced the temperature sensor..

faulty thermostat - ive replaced the thermostat...

ive also replaced the o2 sensor, the one on the front, near the exhast manifold.

all parts that have been used are brand new and are audi spec parts.

before changing the parts the car did run rough at idle, it is slightly better now. also the car is throwing alot of water out of the exhaust.. there is no black smoke though..it has been serviced, i.e oil filter, oil, air filter, spark plugs.

please please help me if you can as i dearly love my audi and really want to keep the car as it is in immaculate condition, however with fuel consumption that bad i cant afford to....

many thanks and all help will be greatly appreciated...

 

Try having the codes cleared, those fault codes could have showed up a year ago, had maintnance done and never reset the ecu... I think that if fault codes are stored, the ecu wont work right unless they are cleared/problem is fixed... So clearing them to see if they come back after a week would be a good idea.. But always write down any fault codes you ever have for your own and a mechanics records. Are you sure your not chipped and have a lead foot? Im not sure which 02 sensor is related to gas mileage, maybe they both are... But you could try replacing the other 02 sensor as well, i dont think its too expensive, and would rule that out, since you already had the temp sensor done... Have you looked at the spark plugs??? GAS LEAK?!

 

thanks for the help..
the codes were read on the 6 dec 2005 and i changed the affected parts approx 8 days ago. ive been driving very slowly and calmly, not pushing the car hard at all...
i will get the codes cleared asap..
also could the MAF be a reason for this???
when i disconnect the maf the car doesnt run smooth at all, it chokes and sometimes dies..
there doesnt seem to be a fuel leak as the fuel gauge remains at the same place untill the car is next driven, also there doesnt seem to be any fuel spillages on the garage floor..
thanks once again for your help.

 

If you have the ability to clear the codes do it. Then do a throttle body adaptation. Turn the key on do not touch the gas and leave it in the on position without stating the car for 5 minutes. Then turn the car off and try starting.

Re-scan and see what codes are present and put the actual code numbers up.

 

thanks.
i do not have a vag-com or cable, so i will get the codes cleared from a garage...
to do a throttle body adaptation do i need to disconnect the battery (positive and negative terminals), or is it done while the battery is connected??
also could the MAF be faulty even if it is not showing on the diagnostic check and how badly can that affect fuel consumption??
can anyone think of anything else that may be affecting my gas mileage...

 

Disconnect the ground (-), reconnect and then allign the throttle body.

 

thanks for all your help so far...

i disconnected the battery totally for approx 8 mins and left the keys in the on position after disconnecting the battery.
due to surrounding noise, i could not hear if anything had moved etc in the throttle body. i then removed the keys from the ignition and reconnected the battery, however when i started the car after reconnecting everything the idle was very erratic, going from 200 revs to 1200, constantly going up and down for approx 1 minute. i took the car for a drive, everytime i stopped the revs would become very unstable, coming close to the car stalling, while driving in gear everything was fine...
after a drive of approx six miles, start and stop, the revs have become stable again...
any idea what is causing this?? throttle body?? throttle vale???

 

ive been told it may be a dirty throttle body...or faulty MAF because the revs starting fluttering after the battery was disconnected then after approx 10-15 mins of engine running and travelling approx 6 miles its back to fairly steady revs, even though they are still not perfect.........
any further help please??????

 

anyone know which wires on the MAF sensor connector are the 5v and 12v wires and which are the signal wires???
thanks...
any help with the above questions please???????
thanks

 

Where do you live? depending on cold and other factors ur fuel economy will be crappy.

this might sound stupid but have you tried cleaning ur injectors?