HELP! Power fc install now mph in sync with tach
 

Anyone know what the deal could be? After I installed my power fc my mph sits a 20mph while sitting still.... I reinstalled my stock one and have no problems

Anyone?

No one has ever heard of this issue before?

Sorry man..Rules are Rules and you keep bumping when you are not allowed to Bump threads in this section.(See Rules Stickied above in this New Member's Tech section)
There is a whole PFC section you can ask about or research this problem,so Kindly use feel free to use it.This is a specialized kind of problem that they are more familiar with and this section is for basic "stock type" car problems.
Good luck to ya.

Further Edit:This Thread is now COPIED and IN the PFC section..again good luck to ya

My apologies man. Didn't realize I couldn't do that. Thank you for putting this in the correct section!

Is this a used or new PFC?

it was a used one. Correct serial numbers and model and also cleared the commander back to its original settings before starting car

I have seen this problem posted, but I have never seen anyone post a solution. The there is a tach signal at pin 2B, try depinning that wire from the connector. This way if the problem is not solved you can just reinstall it.