speed sensor
 

I recently changed out my tire setup on my ZL1 and have 17s in the front and 18 in the back. car keeps throwing a speed senor code which locks me out of reverse, and during high rpm shifting bogs down. Also randomly the speedometer will stop working and not read my speed at all. I would clear the code and 5 minutes later the same issue. Has anyone else had this happen? what did you do to fix?

Thanks for your help

From what I remember, the wheels have to be within a certain percentage diameter of each other. I cannot remember the percentage. Why would you do this in the first place?

drag setup ... skinnies in the front and drag radials in the back

I've read that the front and rear wheel diameters must be within 3% of each other or it will cause problems.

Ah, makes sense now.

I run 17s front and rear with no issues but as others have said I bet its the 17" front with the 18" rear that the computer doesn't like.