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Old 08-28-2004, 08:37 PM
Duke2.6 Duke2.6 is offline
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Join Date: Mar 2003
Location: Southern California
Posts: 2,270
In CA we have drive through inspection stations - similar to a car wash. One not far from me has three lanes and is "test only" (They do not do repairs.), which I have to go to since CA has deemed most Mercs of my vintage as "high emitter profile" and we have to be tested at "test only" stations.

Letting the car sit for 45 minutes - even with 5 minutes of driving is not enough to heat up the converter, and it shows in your numbers.

Find a place where you don't have to wait long and keep the engine revs up as I previously suggested. If possible, drive the car around the block (hard) a couple of times just before you go on the rollers.

These cars are very sensitive to "conditioning" because the converter is relatively far downstream from the exhaust manifolds. Modern cars are going to "maniverters" where the catalyst is literally bolted to the exhaust manifold outlet or as close as possible.

I'm still curious as to your engine and fuel system type. The KE systems seem to be inherently "dirty", and I think it is due to fuel flow variation at low flow rates such as is the case at idle. Pulse type solenoids injectors seem to be better at delivering consistent fuel flow to each cylinder at idle.

In CA some stations will do a "pretest" for a fee. Basically a ripoff IMO, but the pretest will usually get the catalyst up to temp. Also, there is a "tire dry procedure" that can be used in wet weather. The tech runs the car at about 25 MPH with no load for 30-60 seconds, then starts the test. I had this done once and the 15 MPH HC dropped about 20 percent relative to the previous test. On my last test I went on a dry day and the 15 MPH HC was back up - squeaked by with 1 PPM to spare.

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