Sorry about cross posting but I need to fix it ASAP. Smog due soon. I know this has been discussed to death here, but my situation is a little different. Friday I changed the oil and filter on my 348. After taking off the air cleaner housing to get to the oil filter, I thought I would do a little preventative maintenance and clean all the electrical contacts I could see while I had the air filter box off. So I disconnected the battery and began to spray electrical contact cleaner on all the unplugged connector contacts that I could reach. I then took a low pressure air hose and blew the remainder of the contact cleaner out of the sockets and re-connected them. After I was done changing the oil, I re-connected the battery and started the car. I waited about 15 minutes before shutting her down. Then 45 minutes later I took it out for a test drive and immediately the check engine lights started coming on and off and the idle was galloping. I drove it home, checked all the connectors and reset the ecu's. Yesterday I got in and drove to town and the check engine lights started coming on again. First the 1/4 light then the 5/8 light came on and off. Then they both started coming on and off simultaneously. By the time I got home they both had stayed on. Then I disconnected the battery for a couple of hours and started it again last night and let it idle for 15 minutes. In abiout 5-8 minutes the idle started galloping from 2000 rpm to almost stalling, and the CEL's started going on and off. I checked the ECU codes and 1211 (lambda regulation) came up. Question is, what connector is at fault here? Which connector has both sides of the lambda's plugged into it? I've disconnected and re-sprayed every connector 3 or 4 times that I had sprayed previously. I used Caig electrical connector conditioner. I can't imagine both O2 sensors going out simultaneously. What I don't understand is why both sides CE lights are going on and off at the same time.