Intermittent non-repeating CEL codes, thoughts?

[shwanzee]

I have a 1996 960 that has been giving me some intermittent codes lately, that I can't seem to find a common thread, hoping somebody may have an idea. 2 weeks ago had P0102 (MAF Sensor). Last Week got P0410 (Secondary Air Injector Fault), and Today got P0172 (a million things that it can be). My policy is to delete a DTC and if it repeats i look into it. These codes haven't done that, so I am trying to figure out what it could be. I

recently had a bunch of work done, so I am trying to find out what I may have overlooked. This is what I have done since June:

New Air Intake Boot
new evap canister hoses
New Flame Trap & hoses
New Oil Trap Hoses
New Vac hose elbows & connectors
New Fresh Air Hose
New Intake Manifold Gasket
New upstream O2 Sensor
New Fuel Pressure Regulator
New Oil Trap & hoses
New Injector seals
New Coil Packs
New Plugs
MAF 18 mos old (not Bosch)

Is there anything that Could be causing the DTC codes listed above, but to not have them repeating? If i kept getting the same one over and over, it would make sense, but with how they come up one by one and don't come back for a week or so, it is puzzling.

Thanks for the help!

[precopster]

When coil packs begin to break down this was common. Arcing to ground was upsetting my 960. Two years after replacement no codes.

On another car 2000 V70 the regulator was replaced and all my ETM, and O2 sensor codes haven't re-appeared in 6 weeks. Before this despite disconnecting the battery repeatedly and resetting I had a new or repeating code every week. Coincidence? Perhaps though very unlikely.