"Al Kondo" <alkon@hal-pc.org> wrote in message
news:lkjhm2t3uhrf5mnc962h0do8leqmhnh0rc@4ax.com...[color=blue]
>I just had my 91 Toyota Camry Le inspected for emissions. It passed
> everything but NOx. I had the following readings
>
> High Speed Test Low Speed Test
>
> Standard Current Standard Current
>
> HC 123 26 128 127
> CO (%) .69 .13 .71 .31
> C02(%) 14.6 14.4
> O2 (%) 19.7 20.4
> NOx 878 1093 970 947
>
> The part that I am especially puzzled about is the very high O2
> readings. In my test of last year, I had readings in the .5% range.
> How in the world can I get a reading of 20% or more? In fact, isn't
> the atmospheric % of O2 in the range of 20%? Is it possible that I
> had a reading which reflects only that of atmospheric O2?
>
> I would appreciate opinions on what is going on.
>
> Thanks, Al[/color]
Several things can cause high Nox.
Check your EGR valve function by applying vacuum to the EGR while the engine
is idling. If the EGR is functioning properly, the engine will start to
stall if you apply EGR at idle. If the engine starts to stall when applying
vacuum, check the vacuum switching valves that control the EGR. This link
[url]http://oregonstate.edu/~tongt/camry/90/Emission_Control.pdf[/url] explains some of
the emissions control systems, including the EGR valve and controls.
Also check ignition timing and advance.
This link has info for the rest of the car:
[url]http://oregonstate.edu/~tongt/camry/index.html[/url]
--
Ray O
(correct punctuation to reply)
Linear Mode
