[s-cars] emissions results and code 2231 = air leak?

[Sandy Sligh]

Idle vacuum sits at a very steady 14-15 in Hg. How
does this compare to everyone else? Low? High? Normal?

Will renew (i like that word in this context) the o2
sensor as soon as i can locate a tool to remove the
old one.

S

--- Mark Strangways <Strangconst at rogers.com> wrote:

> Renew the O2 sensor...
> Check Fuel pressure against spec at idle. Too little
> vacuum could increase 
> FP thereby rich mixture.
> 
> Pressure test intake system.
> Check MAF against known good, but usually a bad MAF
> makes itself known.
> Check what the actual duty cycle of the injectors
> are, vs..s known value 
> from someone with the same capacity injectors.
> 
> All in all, I bet air leak in a nice hidden
> location, maybe even at the ecu 
> or the line to the ecu.
> 
> Mark
> ----- Original Message ----- 
> From: "Sandy Sligh" <sdslig at yahoo.com>
> To: <s-car-list at audifans.com>
> Sent: Sunday, May 29, 2005 9:59 AM
> Subject: [s-cars] emissions results and code 2231 =
> air leak?
> 
> 
> > Collective Audi Brainpower! Unite!
> >
> > I've located my last three emissions reports. Take
> a
> > gander.
> >
> > March 2003:
> >
> > HCppm IDLE limit: 220
> > HCppm IDLE test: 447 FAIL
> >
> > HCppm @2500rpm limit: 220
> > HCppm @2500rpm test: 151
> >
> > CO% IDLE limit: 1.2%
> > CO% IDLE test: .93%
> >
> > CO% @2500rpm limit: 1.2%
> > CO% @2500rpm test: 1.15%
> >
> > This is the first emissions test after i bought
> the
> > car. The ultimate solution involved a new 4.0bar
> FPR
> > and a new Stromung center section (cat included).
> Here
> > is the result. Note, the limits changed during
> that
> > time:
> >
> >
> > April 2003:
> >
> > HCppm IDLE limit: 120
> > HCppm IDLE test: 48
> >
> > HCppm @2500rpm limit: 120
> > HCppm @2500rpm test: 68
> >
> > CO% IDLE limit: 1.0%
> > CO% IDLE test: .04%
> >
> > CO% @2500rpm limit: 1.0%
> > CO% @2500rpm test: .14%
> >
> > Passed with FLYING colors. Obviously, looking back
> on
> > these results, the new cat was taking up the slack
> of
> > an underlying problem. Here are my current
> results:
> >
> > May 2005
> >
> > HCppm IDLE limit: 120
> > HCppm IDLE test: 322 FAIL
> >
> > HCppm @2500rpm limit: 120
> > HCppm @2500rpm test: 309 FAIL
> >
> > CO% IDLE limit: 1.0%
> > CO% IDLE test: .77%
> >
> > CO% @2500rpm limit: 1.0%
> > CO% @2500rpm test: .74%
> >
> > HC is high again like back in 03/2003 and the CO
> > percentage is creeping back up to where it was in
> > 03/2003.
> >
> > With the high HC AND relatively high CO%, I can't
> > figure out any other reason besides an overly rich
> > mixture. If I assume that Bob Pastore's software
> isnt
> > purposely running the engine rich at idle (no
> reason
> > to), the only thing that i can imagine that would
> > cause a rich mixture would be:
> >
> > A leaky fuel injector? A airleak after the MAF?
> >
> > What else?
> >
> > In addition, code 2231 is present, indicating one
> of
> > these as the possible cause: Idle Speed Control,
> Idle
> > speed adaptation limit exceeded, Sticky ISV, air
> leak
> >
> > Is it time to pressure test the intake?
> >
> >
> > Thanks again for any advice in advance
> >
> > Sandy
> > 1993 S4 CAN
> > RS2: Comp Turbo, MAF, EM, FIs
> > 26lbs Pastore software
> > Stratmosphere bypass
> > Eibach/Bilstein
> > 996tt calipers over 993tt rotors
> > Stromung 3"
> >
> >
> > _______________________________________________
> > S-CAR-List mailing list
> > S-CAR-List at audifans.com
> >
> http://www.audifans.com/mailman/listinfo/s-car-list
> > 
> 
>