Do you know how old the O2 sensor is? Anything more than 60,000 miles is
suspect. 90,000 miles is past its prime. Even if it is 'working', when they
get old they slow down (response time) and the computer may decide to ignore
a slow response - defaulting to its slightly richer map.
Was the catalytic converter fully warmed up? Even if the car had been driven
for a while before the test if it had been parked for a little while before
the test the catalytic converter could have cooled down. Maybe.
Eric Russell
Mebane, NC
http://home.mebtel.net/~ejrussell
----- Original Message -----
From: "alfa-digest" <[email protected]>
Date: Mon, 7 Feb 2011 00:21:15 -0800
From: Charles Slayman <[email protected]>
Subject: [alfa] Marginally High CO Emission from L-Jet Spider
Dear Alfisti,
I just failed the bi-annual California emissions test on my '89 L-Jet
Spider for marginally high CO at 25mph. Here are the results:
2801 @15mph, Max CO Allowed 0.78%, Measured CO 0.78% PASS
2870 @25mph, Max CO Allowed 0.66%, Measured CO 0.78% FAIL
The other tests (HC, NOx) passed and actually get better with speed, so
the
catalytic convertor is working. This looks like a problem with the
mixture
running rich. The O2 sensor is working and the temperature sensors are
working (so the L-Jet is not running rich intentionally because it thinks
the engine is cold or the O2 sensor is dead and defaulting to a rich
condition).
Have any of you experienced a rich condition on an L-Jet that was not due
to
a dead O2 or temperature sensor?
Thanks,
Charlie
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