The car ran beautifully on the way home tonite and there were no codes on the built in reader,,,, code 13 on the 8 pin on your reader though. :eek:

Ok
That's an indication we have not solved it..
What we are looking for is unmetered air ..Here is another common possible. The cross over pipe from the MAF.. it should have good connections at the MAF, a little further up the line you will see an Air Temp sensor..make sure that is tight , and finally . [ and this is common] where the hose finally clamps to the intake there is a round clamp about 3" in diam..this has to be tight and you can only tighten it by sneeking in there with a long screwdriver from the front of the engine..try that..
You may also want to cap that purge and try a few trips w/o it.
Did you do the CRC MAF cleaning I mentioned..???

...and , check you do not have a dirty air filter.

Will clean the MAF today and check all the connections. Read Jim F's tutorial on cleaning the MAF,,,, pretty thorough piece.

Unlike the 400E, which is a thin wire, the MAF seems to be a little plate,,, looks clean but I got a can of the CRC MAF cleaner. The air filter is clean and all the connections are tight. I even took the short accordion hose out and inspected for cracks,,, none.

<<the MAF seems to be a little plate>>

Yes . You have HFM system..that stands Hot Film Mass. So ,this is not Hot Wire like the older LH systems.
But , that plate gets an oil/dirt film on it that effects the sensitivity and ablity to read air mass... more so than the hot wire ones do [ they burn it off]
Anyway, you know the deal..reset and drive it, watch for the change. Might also want to cap the vac line going into the purge for a few drive cycles at the same time ..that way , if all turns out OK , you can return to purge and if comes back then, you know the MOT is not closing .if that is the case, seeing that you have cleaned it, I would replace it..but not until you have verified where you are at.
An Indie/dealer would be looking at these adaptation numbers, but it can be done diyer this way, just takes some patience/time and monitoring.
Try and get that 02 sens cleaned up with the hill trip too..you know it is carboned up b/c of the past condition of a/f mix..you want that to be clean so it can work fast to help keep the trim in place..

Disconnected and plugged the purge valve, cleaned the MAF, beat it like a rented mule on the longest hill we have around here, brought it back and the surging is about as bad as it's been. I recently had a new EGR tube put on,,,, I wonder if the bolts for the intake have worked loose ? I'm going out to check.:confused:

Did yu clear te memory after cleaning the MAF and capping the purge..that has to be done just like before .