1991 Chrysler TC by Maserati

[Jefe]

Hello everyone.  
 

   I have an issue with my car.
 

  When I start the car, the speedometer starts to waive at me and settles at 125 miles per hour. All the way to the right and flickers back and forth. At the same time the car thinks I am driving and the odometer starts to record the miles. Yes. You can see the odometer counting the miles as if I was driving.  While parked I saw 10 miles added without driving the car.  It all started when I failed the emissions test. I have replaced all the following in hopes to pass. 
 

6 spark plugs

oil filter

oil change 10/30 synthetic  

distributor cap & rotor 

Map sensor 

o2 oxygen sensor

Automatic  idle speed motor. AIS

Throttle position sensor. TPS

out speed sensor

in speed sensor 

Throttle body cleaned 

Speedometer Transmitter on transaxle 

fuel filter 

air filter

 Anyone hear of this happening before and the solution? 
 

I appreciate any help. 
 

Jeff 

Edited June 1, 2022 by Jefe
Update (see edit history)

[EmTee]

If I recall correctly there was a period of time where Chryslers of this vintage had issues with speed sensors.  That's the first thing I'd check...

[ted sweet]

my 91 lebaron does same thing hoping changing the sensor fixes it,