Chevrolet Repair: 98 S10 misfires during cold weather, chevy dealer, cold weather

Question
'98 S10 LS pick up 4x4, 4.3 automatic, 125,000 miles. When the temperature drops under 20 degrees it will misfire untill engine warms up completely. Service engine light will come on and sometimes there will be a jolt when it's put into drive or reverse. When the the temperature rises it runs fine and the service engine light goes off. I recently had the transmission serviced, intake gasket, spark plugs and I believe distributor cap replaced.

The Chevy dealer wet tested the engine and found no problems and also found the following codes: C0226, P0122, P0405, P0452, P0507 and P1122 but could not pin point the problem. They told me to bring it back in when it's running poorly. I appreciate any help. Mark

Answer
Hi Mark,
See if they replaced the plug wires.
Then...is it possible you have some water in the gas?
Lastly....check the temperature sensor. See this link.

http://www.chevytalk.org/threads/showthreaded.php?Cat=0&Number=1366279

Any chance you can leave it at the dealership overnight....parked outside?

Van