A few years ago I purchased an 04 ECU with immobilizer and key for my 05 TSX so I can get it reflashed. I recently lost my car key so now i'm back to the stock ecu/immobilizer/key. I would like to match one of my spare keys to the 04 ECU. How do i go about doing that? Do I take the 04 ecu and immobilizer and unmatched key to a dealer and they would do it with no hassle? Does anyone know the cost? Thanks.

 

A locksmith could do it for around $20 or less. I'm not sure if a dealer would charge you or not.