2001 dodge van 5.2 1500 4 speed auto overdrive

Really needs to be 'scan tested' to help find your 'engine misfire'..!!

just had it scanned and it came back with a code 1740

That was a code reader... not a scanner!! If it were 'scanned' by a qualified mechanic, you should have been told where the problem area is! That is a transmission code.,. scanner needed while test driving to view live data... Include all info next time you post a question for a more accurate answer!... The first time.!!