My Accord with H22A is in Limp mode, no any Code, no Vtec engaged and cannot pass 6500 rpm. Only a unknown error is recorded and noticed by the scanner. I m using a P13 ecu with Manual transmission.

I have checked all sensors but nothing was found. I am thinking about to replace a ecu which is not limit by protection. Should I get a Hondata S300 or a chipped ecu?

I am not the specialist on this and hoping can get some advise from you guys