Currently GM stage 2, k&n intake. i just put a 2.9" pulley and ported my m62. i had the zzp ls4 tb with a zzp canned tune which ran great earlier this week until gm fucked up a crank relearn by reflashing the shitty as **** gm tune back into my pcm - im currently waiting for my zzp pcm to be sent back. Anyways, tonight i get a bank 1 too lean code and then notice my boost pressure is extremely low especially in higher RPMS. Ive seen a few people say theyve discovered it was their cat, but others say that increases boost. My opinion is if theres restriction boost it goona be cut by the ECU to prevent any damage, dont see how it'd increase with all the safety gm has on the lsj. Another thing was sc gasket, i noticed it bent a little when i took my blower off and i straightened it as well as i could when putting it back on. Would the port and pulley have an affect on losing that much boost pressure? is there anything non costly i could do to attempt to cure this problem? would really appreciate some positive feedback, thanks!\

ps. on idle my boost needle is -70

 

try posting this in the problems and service section

and google the boost bypass mod