hmmmm has your car ever been hit on the front passenger fender?
with my car my ecu got shorted out so wheneva i hit around 4500 it would putter and lag past it. basically for me my engine was tryn to go thru its VTEC stage but wasnt recieving the signals from the ECU i had to get a whole new ecu. might not be your problem but thats why i'm asking about the accident