hey guys my speedometer says i am going 60 when im going like 40, and 20 when im stopped. But sometimes it works just fine, and sometimes its only off my 5 mph or so...what should i do?
thanks

 

I have the same problem, some days its closer than other. Now mine isnt that bad, but its off like a good 7MPH atleast about all the time. I would just take it to the dealership, but they are gonna take you to the cleaners

 

if you get bigger rims/tires which guessing by our pic you did it will throw off the speedometer you can try and find the difference or have it re-calibrated.

 

This sounds more like a sticking problem in the speedo or maybe something electronic and this should be under warranty as long as your not past 3 years or 36000

 

haha have fun going back to stock tune if you bring it to the stealership
lol anyways sounds like warranty work since its variable

 

yeah it could be because of getting larger tires, or if you obviously didn't re-flash (or tune) your engine properly. But otherwise, I would go straight to the dealer on that one.

 

The cluster or the PCM is giving the wrong reading.
Check your HighSpeedCanBuss wiring.