How about the ignition system, plugs, wires, cap, and rotor?
A slight misfire would send the HC's up.
Being in California you should have access to street legal racing fuel.
Like Cam2 GT unleaded.
It is Oxygenated, and will burn more completely due to it's lower boiling
points (distillation curve).
I always fill up with Ultra before smog tests.
If you have a low temp thermostat swap it out for a stock one.
Good luck.
----- Original Message -----
From: "rws" <rwsam2002@yahoo.com>
To: "DakotaTruck DML" <dakota-truck@dakota-truck.net>
Sent: Thursday, September 27, 2007 5:36 PM
Subject: DML: Re: 94 Dak 5.2L Cat Converter Air Pump or Air Switch Valve?
>
> Biff,
>
> Oil and filter was changed. Using oil branded for "older" vehicles. I
> think they put some copper in the oil to keep it running quieter, but
> need to verify.
>
> New O2S.
> New ECT sensor.
>
> Used Chevron's injector cleaner just prior to test, about a month ago.
> a BMW dealer says its the best they found to keep injectors running
> clean not dripping and remove the built up carbon on pistons and
> valves.
>
> PCV valve cleaned and checked and I can hear it making noise with
> engine running. Shop manual says this is a good sign.
>
> The EGR valve was replace 2-3 yrs or 11-15k miles ago. Maybe low oct.
> fuel can make it dirty again? I don't know. I tried to clean the EGR
> with solvents befor getting a new one. They are hard to clean so that
> they shut completly and smoothly, that's why I just got a new one. How
> long should they last?
>
> If I give up and take it to a CA certified smog mechanic, what will he
> do?
>
> Anyone here in California? Have you noticed the smog test criteria for
> the three elements gets lower the older the vehicle is?
>
> Ron
>
>
>
>
> -----------------------------
> Re: 94 Dak 5.2L Cat Converter Air Pump or Air Switch Valve?
> From: Biff Byrum (bbyrum9@foothill.net)
> Date: Thu Sep 27 2007 - 16:54:30 EDT
> -----------------------------
>
>
> Yeah, I had about the same results. Just passed by one. It's said that
> leaky
> injectors and the O2S are the leading causes of HC failure.
>
>
> Excess carbon buildup in the chambers can cause this reading. Someone
> sugested B-12 Total Combustion Chamber Cleaner. Also suggested was
> changing
> the oil so the new oil can absorb more HC. Remember that you do have
> that
> silly, prone to fail EGR on that engine. Also, new PCV valve? Biff
>
>
>
>
> ____________________________________________________________________________________
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>
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