I have just had my engine rebuilt following a big end failure.
I have gone for 'like for like' pistons and upgraded STI rods as the original rods were only 'thin' WRX equivalents.
I've had some hesitation with low speed driving, since the rebuild, and my mapper says that as the engine has been rebuilt it won't be the same as it was and hence I will need it re-mapping again. I know this is the 'safe' option but he lives 3 hrs drive away and of course will charge me another mapping session!
The hesitation has now gone away again and the car now 'appears' to be driving well throughout the entire rev / load range.
I know many people get their cars re-mapped using open source ECU Flash / Rom Raider etc. simply by sending some data logs to their mapper who in turn makes some tweaks and sends a new map back to be flashed onto their ECU.
My question is can I determine if my car really needs another re-map by getting someone to review some data logs taken via Rom Raider or is it necessary for a mapper to hook up to the car with a wide band lambda sensor and PC in order to determine if a remap is necessary?