Is it possible to get a code 24 with a working spedo? I'm using winaldl and it shows the mph just fine other than being 10 mph fast, what would cause that? I'm afraid with the code set it might not let ecm retard timing when I get into knock. Being that there is a mph threshhold. By the way this is a "747" hybrid setup in a monte carlo.

 

Yep.
Most common thing I've seen is some lube from the speedo cable getting on the optical shutter in the back of the speedo. If your Monte uses the same setup as the 3rd Gens. Thou every once in a while the little sensor does die.

In you sig, it says 3.25 gears, did you change the speedo driven/drive gear to match the new ratio?.

 

Yeah I changed the gears in the tranny to the ones that match 3.23's close enough. But the speedo reading shows up in winaldl just fine other than being fast by 10 mph, do the vss filter constants change this? My real question is will it keep things from happening in the ecm if the code is tripped. In the meantime I unchecked the error codes so I "assume" that the ecm thinks everything is ok. How many errors does it take to envoke limp home mode?