Good news, I was able to tune out the EGR and code 26 from my 92 vette. now i have another question. What all do the companies change when they say they can send a custom chip to gain 10-15HP? how do they do that without datalogging?

after i datalog what are my first steps to tune? is the ultimate goal to get the BLM to 128? Theres soo many scalers and tables that are able to be changed but i would think a sorta simple tune would only require changing a few things like VE tables, Spark Advance, and fan temp turnon.

Thank you greatly for the help on finding the right XDF.