In article <425F3AB9.5A56FD1D@BottomOfMessage.com>,
> "System too rich (Bank 1)"
> I've been fighting this thing for a while and frustration is building.
> It can take up to ~240 miles for the code to come back when reset, less
> when it's warmer out.
> Based on the code description and what the dealer was planning to do I:
> (1) replaced the Mass Airflow Sensor.
> When that didn't work I discovered this group and tried the following:
> (2) Replaced all of the rubber vacuum elbows even though most of them
> seemed fine.
Even the one behind the power steering pump that you can hardly see?
> Any other ideas? Things I can easily check?
Any unmetered air entering the intake stream after the mass meter will
drive the system rich, i.e. intake manifold gasket, crack or split in
the intake bellows hose, exhaust crack or leak near the O2 sensor.
Possible cam timing issue.
When checking/replacing the vacuum hose on the fuel pressure regulator
was there any whiff of gasoline? Any trace will justify condemning the
regulator. Hang a gauge on the fuel rail, the regulator can stick
intermittently, and see if you can catch it raising the fuel pressure
when the MIL comes on.
Make sure the coolant temperature sensor is sending a valid reading to
the control unit.
> If I can find someone with OBD2 software will I be able to learn
> anything by looking at the snapshot data when the code was triggered?
Only if you can identify the bad reading from a component you already
suspect. Typically what you'll see is a collection of all the bad data
that were present when the code set. IOW, O2 readings will be rich, long
term fuel trim will be cranked all the way lean, short term fuel trim
may be adapted lean as well, injector dwell or frequency will be high,
manifold vacuum will be low, barometer may be inaccurate, MAF signal
will be rich, load signal may or maynot agree with vacuum readings
depending on throttle position switch interpretation, and so on and on.
Mixture codes are more typically from the electronics reporting a