Still low mileage

["Peter Plangger" <pepe@z.zgs.de>]

Hi Q-listers,

first many thanks to all who responded to my low-mileage problem. Most
said that 10% increase in fuel comsumption at 145000 km was typical
for a bad oxygen sensor. Special thanks to Rob Winchell who directed
me to a universal Bosch sensor that cost half as much as the stock one
(69 USD).

In the meantime I have used an amperemeter to test the lambda system
according to my manual. I let the engine run at idle for two minutes
and the amperemeter showed 0 to 10.1 mA. The current was slowly rising
from 0 to 10.1 mA in about 10 sec and then dropped to 0 in no time and
then began to rise again to 10.1. The dropping from 10.1 to 0 made a
change in the engine sound.

Then I pulled the dip stick. Idle dropped a little for a second and
amperemeter showed 10.1 mA now constantly.

Then I pulled the oxygen sensor cable (with dip stick pulled) and
pressed the green end to chassis ground for 20 sec. Current still 10.1
mA  constant.

Has anyone ever done this before? Are the values and the behaviour
(mine and the car's) correct? The car is a '91 Audi 90 2.3E, 133 HP,
145000 km, non quattro, AC. I have also pulled the codes, but only
4-4-4-4.

BTW, I have been moving this week so I was unable to download my mail
for a few days. It will take some time to get up to date. Still 1300
unread mails *whoa*.

Happy weekend to you all,
Peter

_/_/_/_/_/ pepe@z.zgs.de \_\_\_\_\_