I have a '94 940 Turbo wagon (208k miles). CEL came on about a month ago. Since then I have fiddled with it and gotten 2-3-1/2-2-1/1-1-3 codes in A2.

So I replaced the oxygen sensor. It was fine for a few days then came back on halfway between Atlanta and Charleston. Replaced the ECT and flushed coolant. Came back on almost immediately.
When I was doing this I took the throttle body off. Noticed it was a little wet on the butterfly valve on the downstream side. That turned my attention to the fuel pressure regulator. Replaced that with a unit that hadn't given me trouble before. CEL didn't come back on for a few days, but now it's on again with just the rich/lean codes.
I've sprayed around the engine bay with starting fluid to check for vacuum leaks to no avail. Tested voltage and resistance on all associated sensors and AMM and all look to be good. PCV doesn't seem to be backed up.
I'm going nuts over here. Can anyone please help?

 

Cool thanks for all the help guys

 

This may be a shot in the dark(actually 2 shots). My '93 turbo seemed to run well but had a sooty tail pipe. Then it would start intermittently. I replaced the crank sensor and all is well. If you're getting a code that the mixture is lean but your butterfly is wet then I'd say ignore the codes and look at the symptoms. Your problem may be electrical? Also, heard many times here that a bad temp sensor will keep the system in cold start(rich) mode. So that's my 2 shots - not burning what you got or getting too much.