Chrysler Repair: 95 lebaron 3.0L engine acting strange, digital communication system, speed sensors

Question
i hope you cna help me with this.my daughter has a 95 lebaron convertible that she bought a year ago. she was driving it one day and the tachometer started bouncing went to max, the speedometer also went haywire, the engine started bucking and then shut off. after stopping and waiting a few minutes it started back up and ran fine for a little while and then repeated this problem. there are two control modules under the hood i replaced the one on the passenger side but the problem persists. i was told this could be caused by the speed sensors. do you think that could be the problem  

Answer
Hi Tom,
I would try the memory of the engine controller to see if it has any stored fault codes. Turn the ignition key:"on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the check engine which remains 'on' to see it begin to flash, pause, flash, etc. Count the number of flashes before each pause. Then repeat the procedure to assure an accurate set of flash counts. Group the counts in pairs in the order of appearance to form the 2-digit fault code numbers. The last number is always 55 because it means 'end of fault code readout'. Then write back and tell me the other codes or go to www.allpar.com/fix/codes.html for a translation of the codes.
I doubt it is the speed sensor as that would not affect the tachometer. More likely it has to do with the digital communication system between the various controllers which include the engine and the cluster but lets see what fault codes you find.
Roland