OK I put a new head gasket in my evo 03 and when I went for a test run I saw that I was hitting 23lbs of boost and I was told buy the guy I got if for that it was set at 18lbs so I lower the boost and now I CAN"T REV OVER 4500RPM and it is making about 9 to 11lbs of boost. I have a switch for my AEM one setting is for 93 at 18lbs and the other is for 110 at 23lbs. I for got that I had this switch before I lowed the boost. I tried to raise the boost but nothing happen. So I really need help on this one

 

Bypass the AEM and run stock management, test if it's the piggyback. You may be in limp home mode get the codes scanned. Recheck the timing the old DSMs sometimes skipped an exhaust tooth when you did a timing belt I'm not sure but it's almost the same setup. Some back-story may help... Why did you need a new head gasket? Is it stock or aftermarket and if it's aftermarket what type.

 

The head gasket is a stock one and I don't have the stock ECM it didn't come with the car. I will use a scanned tool today to see what it is. Thanks

 

I think I may have found out why I can't make any boost. I was looking on some other forum and I read that other people were having the same thing happen to them and It's a boost leak or a bad wastegate. I had this happen the first time when I got the car when it wouldn't let me rev over 4500RPM in neutral. So I was thinking it was a launch control set up for the AEM. I have a way to test the wastegate to see if it's bad. It make sent because the wastegate is what make the boost right and by using a boost controller you are controlling the amount of boost that the wastegate makes. I have tryed to raise mine back to 23lbs and know matter how much I raise the boost up it wont make over 10lbs.

 

Wastegates don't just go bad often. I would check something else. Sounds like you're having a problem with your boost control system. With a boost controller, you're controlling how much boost the wastegate is able to sense. Try a different boost controller, that's more likely to fail than a wastegate I think.