[s-cars] mileage with MTM1+

[Tom Green]

Konstantine,

I would not get too hung up on the O2 sensor since there can be many  
other
causes for poor mileage.  Don't ignore it but check other items as  
well.  Many
other items that are over 15 to 20 years old could be failing-except  
the driver.

You have not indicated any other maintenance performed recently.  The O2
sensor should show codes if it has big problems, and other problems in  
the
engine may be reflected by codes indicating the O2 sensor cannot correct
the fuel mixture and reaches the maximum or minimum voltage correction.

Look for issues as you would with any gasoline engine-routine  
maintenance
for a clean air filter and intake passages and valves, spark plugs and  
boots in
good condition, injectors may need cleaning, condition of the vacuum and
emission control systems, boost hoses for any leaks, and the temperature
sensors that send signals to the ECU.  All these can affect your fuel  
mileage.

Sometimes you get some hints where the problems lie from rough idle or
miss at low rpm or on boost but not always.  That is why some things  
just
have to be done regularly according to a maintenance schedule.

And don't forget, the President says you can get 2 mpg by inflating  
your tires
properly.

Tom '95 S6
          '95.5 S6 avant
Knoxville, TN

> -----Original Message-----
> Date: Tue, 31 Aug 2010 12:36:20 -0400
> From: Konstantine Bogach <kbogach at comcast.net>
> Subject: Re: [s-cars] mileage with MTM1+
> To: s-car-list <s-car-list at audifans.com>
> Message-ID: <7BE23434-D46D-4A5E-8BA9-ECDCF5E1A166 at comcast.net>
> Content-Type: text/plain;	charset=us-ascii;	format=flowed;	delsp=yes
>
> Based on responses (thank you!)  I think I have a problem somewhere.
> 18-20 mi/gal on average on RS2 convert is much better then me having
> max. 18.5 with only MTM 1+ chip at mixed driving (I even would not
> call it "city" around Princeton, NJ).   Cruising on highway at ~78 mph
> does not make it better than 21-22 mi/gal.
> What should I check?  Ok, I will go over O2 testing again (1 year old
> one).  What else?   Can MAF be failing gradually?
> Thanks.
> Konstantine