[V8] Forward #10: Failed Emissions Miserably

[george.fallot at verizon.net]

      I had a similar problem.The new o2 sensor only lasted a few months.I
found that the coolant sensor was bad.This is the sensor on the back of the
right head.I changed it and the car still ran rich.I then replaced the o2
sensor again and it passed with flying colors.
     If you pull the codes it will tell you what's wrong.If the o2 sensor
code comes up,disconnect the black wire from the o2 sensor.It is connected
near the firewall near the rear of the left head.If the car runs better
without the black wire on, you need a new o2 sensor.If there is no change
the trouble should be the fuel regulator.
     The key is pulling the codes,it's not that hard.If you need a new o2
sensor I would put in the 4 wire Ford sensor, you can by it for only $50
(bosch #15716).
    Good luck,George
----- Original Message ----- 
From: "Buchholz, Steven" <Steven.Buchholz at kla-tencor.com>
To: <v8 at audifans.com>
Cc: "Campozano, Robert" <rcampozano at mgmmirage.net>
Sent: Tuesday, November 29, 2005 5:24 PM
Subject: RE: [V8] Forward #10: Failed Emissions Miserably


... not so sure I'd agree with the "OXS is the first suspect" comment.
Certainly, if the OXS is old it may be the culprit, but if it is fairly
fresh you're more likely to be shooting the messenger ... my sentiments
are similar for the FP regulator ...

There are a good many components which can contribute to a high HC
problem ... I think many of them have been pointed out in earlier
messages.  If the ECU thinks the engine is cold it will deliberately
richen the mixture.  If you've got a flaky injector or a problem with
spark in a cylinder it can create the situation too.  As I recommended
last night, my next step would be to pull the spark plugs to see if it
appeared to be an issue with one or a couple cylinders, or if it
affected the entire engine equally.  This will guide you to the next
step of problem identification ...

Steve B
San Jose, CA (USA)
>
> I will do that but the 02 sensor is only a year old.  Is there
anything that
> could have damaged the 02 sensor?  If that is the case I want to fix
that
> before I replace and have it go bad again.  Thanks for the quick
reply.
>
> >
> > Put a new O2 sensor on it.   Would be the first suspect.   Did you
pull
> > codes?
> >
> > -----Original Message-----
> >
> > So, if I were as rich as my car is running right now I wouldn't be
> > having
> > this problem...I failed all aspects of the emissions test, all of
them.
> > Results
> > are:
> >
> > HC ppm
> >
> > Limit   Reading
> >
> > 220      687 (2500+-300)
> >
> > 220      1208 (Idle 775+-425)
> >
> > CO%
> >
> > Limit   Reading
> >
> > 1.20     9.95
> >
> > 1.20     10.62
> >
> > What's really bugging me is that I replaced the 02 sensor over a
year
> > ago
> > (passed then with no problems).  I also replaced the Fuel Pressure
> > Regulator
> > about 4-5 months ago.  What else could be affecting this?  Right now
I
> > am
> > assuming that I have a prematurely failing 02 sensor.  What else
should
> > I
> > look at?  The only other recent work I have done is PS hoses and
fixing
> > most
> > of the problems with my instrument cluster.  I have 10 days to fix
the
> > problem so any immediate ideas are greatly appreciated.  Thanks...

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