Hello all. I recently purchased an 84 850 Turbo wagon with 104K on it. It had a reasonably good service record and after I got it home, I cleared the codes (knock sensor and something about the cruise control) and reset the service light. No codes returned.

I replaced the cabin air filter, spark plugs, plug wires, cap, and rotor with OEM parts. I swapped out the OEM air filter with a K&N. I flushed & filled the trans with Mobil synthetic, and changed the oil to Mobil One and used an OEM filter. I also pulled and cleaned the throttle body, replaced the turbo oil line seals, replaced the thermostat and fixed a vacuum leak. You get the picture.

I have put about 1000 miles on the car and it has performed flawlessly. On the way home today, I got the dreaded check engine light. Here are my codes:

A2: 143:knock sensor, front: signal missing or faulty
B1: 211: driver's side damper motor position sensor: open circuit or short circuit to supply voltage
A7: 122: ECT sensor interval too long
A7: 113: fuel level sensor open circuit

Now it gets wierd
A6: nothing. No 111, nothing

Even wierder, I can't clear any of the codes. Just to double check, get all the codes off any given socket, then do the 5 second press, wait 3 seconds for the light to come back on, another 5 second press, then release and check codes as normal. Right?

Here are my questions:
1) Is the timing automatically retarded when you get a knock sensor code? This is something I read on another site.

2) On a car of that vintage, is it the knock sensor, wiring or crappy gas that usually causes the code? I've been using 92 octane unleaded, but I can switch brands if need be. I have not noticed any ignition pinging.

3) What the heck does that B1: 211 code mean? I was driving to work this morning and saw that the Recirc and AC Off indicator lights were flashing in unison. I turned off the fan and reset the temp controls on both sides to 70 from where they were at 60. Is the code related to this and why did those lights flash?

4) How do I clear those codes?

Thanks for your help,
Bert