[Timing belt procedure without integrated tensioner]

Did you get it yet Basket_Case? Doing a '98 with the old style tensioner right now. Had to go a couple years back in the service manuals to find an example with the old style. Seemed odd. Was held up by a gasket taking it's sweet time to the PO Box... Progress Made 

[Idle Air Control Valve Cleaning... Problem..]

Hate when no answer  is given;

 

Shorted lead for the harness. Everything tested out clear for voltage, so i didn't follow that lead.replaced the harness, Just throwing ideas, after all, multiple valves were tried, all cleaned...

 

New harness, still no go.pulled on the wires some, so the crimps were out of the way... Presto... been running ever since.

[Engine Problems in 1991 Legacy 2.2L]

Not to beat the dead horse, but I have the exact same scenario with my 1991 Legacy L 2.2 Automatic. Then it went away for a month, then came back to stay. It was throwing all kinds of codes... too many to make any logic, but swapped the plugs, wires, fuel filter, and O2 sensor, figuring that these things would need to be done soon anyway. Also, pulled all the injector electrical connectors, cleaned them, and put NoOx in case (cant hurt). Only code left is 15 for injector #2 Abnormal Signal... Considering buying a new injector or a whole set..

[50 50 mod will it cause harm to the transmission?]

Bump - I'm curious about this as well.. Winter is coming and it would be cool to hear from somebody who has run this mod for a few years now...