?s re VAG-COM Readings

QSHIPQ at aol.com QSHIPQ at aol.com
Thu Sep 18 22:47:32 EDT 2003

[ Picked text/plain from multipart/alternative ]
First fuel injector test:
pull the electrical connector off each fuel injector.  When you get to the
one that doesn't change the running motor sound, that's the cylinder with the
problem (spark OR fuel).  Then, you can swap it for another one in the bank, to
see if the suspect cylinder comes back.  If you already have the O2 sensor,
swap it in and see if it works.  IME with 02, the first indication in the
failure is a massive drop in the fuel mileage.  They also tend to become slow to
react.  If you hook up a no load voltmeter to the 02 and read the voltage while
blipping the throttle.  Or if you can get a reading from VAG com or other test
equip, you should see lambda approach .9 as you blip the throttle, then return
to 1.0 +/- within a few seconds of releasing the throttle.  IME 2 O2 sensors
bad tend to run on the rich side, not the lean side of stoich, and lean is
what you have IMS.  When I see lean O2 readings, I think either air leak or bad

I'd also caution again that sometimes 02 sensor codes are because something
else is causing them to happen.  New O2 might solve the problem, my concern
would be that it's just covering up the problem.  In which case, in my case, it
would be back in my shop, in your case, we might well revisit this thread.


Scott J

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