I drive a 05 evo VIII. It has a turbo back exhaust system, intake, mbc set at 21 psi, and ecu reflash. I recently was driving home from work and my check engine light was on after I tried a 3rd gear pull onto the freeway. I floored it and the car hardly moved at all. I looked at the boost gauge and it would go only to 16 psi. Read the code and it was random/multiple cylinder misfire. I researched on the forum about this and people say that this can happen with evo VIII and isn't that uncommon. i cleared the code and the car hasnt thrown a code since, but still only boosts 16psi. I was thinking it switched to a more conservative map when it threw the code. do i need to get another reflash or can i just raise the boost?

 

did i make any sense

 

i guess i'll just raise the boost up and see what happens... hopefully no codes, but thanks for the help

 

did u check ur spark plugs? i had this problem too and changing the sparkplugs solved mine. good luck

 

just picked up new ones. if a plug goes bad does it make you boost less?

 

yes, causes misfire.
Swap out the plugs and then re-check your couplers, you may have boost leak.
Leave whatever boost setting was set it when you got it reflashed.