I have a99 with the 5.2 engine, and have found during cold weather the upshift to 3rd is about 8 mph later than normal. Does any other people have a similar problem, and if so was it resolved, or do we just live with it until warm weather???

this might be the prob, your trans is hydrolic in the first and 2nd gear then it goes to electric,on cold days the hydrolic transfer to electric can cause it to be a little slow,,,,no worries

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2001 5.9 with heads ,cam,alum. roller rockers,headers,true duals with 40s flowmasters,55 milim. tb,mopar intake new fuel rails,,and so on....