My speedometer has some really weird issues. At any given point it is usally 15 to 20 mph off but if it's cold started I've seen it almost 50 mph off (on the highway). What could be causing this? I replaced the VSS and it ended up not being the problem. Any help would be much appreciated.

Cliffs
-VSS is 15-20mph off, even worse when it's cold
-Stock tire size & rims
-95 LS w/B16 transmission
-New VSS
-Also my temp gauge doesn't work (if that matters)
-odometer is accurate

 

Is this a DA or DC?
cel?
How's the cranking?

 

Maybe its a short in the wiring between the gauge, VSS, and ECU.Try trouble shooting the circuit with a voltmeter if the manual gives you a diagnostics checklist. I've never seen a partial failure of the gauge, but after I installed my Alpine headunit I had a few instances where my dashcluster completely shorted out due to a lose wire that wasnt capped or grounded before installing the stereo, that I've since took care of.

 

OP stated had a 95 = dc

inaccurate speed readings would result in inaccurate odometer readings btw. if the vss is good and installed properly i would try a different cluster and/or ecu, see if it still does it.