Date:         Fri, 23 Aug 2002 08:47:45 -0700
Reply-To:     Doktor Tim <doktortim@ROCKISLAND.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Doktor Tim <doktortim@ROCKISLAND.COM>
Subject:      Re: Bad Cat = No Smog?
Comments: To: van man <vannman99@YAHOO.COM>
In-Reply-To:  <20020823152327.20495.qmail@web14902.mail.yahoo.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 08:23 AM 08/23/2002, you wrote:

>IDLE 0.17% CO 135PPM HC

That's at the tail pipe, right???

>Before CAT at IDLE 3.65% CO 290PPM HC.
>
>I have already order the new cat and will replace it
>tomorrow, but was wondering what you smog pros thought
>about this diagnosis.


The tail pipe reading says the cat is functioning properly, but the pre cat
reading says way too rich. This will eat the cat. Get the motor running
right before you spend your money on unneeded parts. If this mechanic can't
verify why you're not in spec, find a better mechanic. This could be
anything from poor compression to fuel pressure regulator to just dirty oil
or worn plugs, or not following the proper set up procedure for timing
adjustment. Make sure your mechanic has the Bentley and follows procedures.
Verify mechanicals, then ignition, then fuel delivery. With a properly
tuned engine, the before cat CO should be not more than 1.5%, a nice tight
motor will be as low as 0.8%. See the spec on the label inside the engine
hatch, 0.7-1.1% if memory serves. You want the lowest reading within the
spec range that provides smooth idle. When that's in spec, the cat will
purr like a good kitty with 9 lives.