i done the mod and finally got all the vacumes fixed so now its not suckin air from nowhere....BUT...where did all my bottom end power go? it has nothing now on botton end ...mid and top end are the same ......is this the side effect to doing the egr mod?

 

Try resetting the computer. Disconnect the battery for about 15 mins, and see if that fixes it.

 

i thaught the newer model cars automatically configured or "learn" new things or how ever you put it ? with out resetting the computer

 

^ resetting the computer for 5+ seconds still 'erases' drive info... But the LSx platform learns within seconds.. -They do not require a full drive cycle like the 3rd gens did.

 

i dint think so ..but ill still try it

 

Cheap and easy first.. if it didn't work, it didn't cost you anything.. Ya know? Other than that, I have no idea what would cause a drastic low end performance loss.. Unless you may have forgot to plug the EGR valve back in or something. -Even that wouldn't do it, IMO..

 

They do, but it's an extremely slow process, and it can only compensate so much. It's not like the PCM will detect that 427" engine you just swapped in and learn the optimal PCM calibration Best thing to do is to reset the PCM and start from the factory presets - it will learn quicker that way. Regardless, it WILL require 2 full OBD-II drive cycles to go through everything.