cat 3406e low boost??

i dont know if you said it but check fuel pressure and for a cac leak also. not just the boots but pressurize the cac and see if it holds pressure.

 

I think you need to fix it before you turn it up.

 

X2!!!!!!!!

 

You have a 99 truck so I would start by replacing all the fuel lines. The sensor is in the cylinder head above the air compressor. When you're loosing power when you hit top gear it is often a fuel supply issue as top gear demands the most fuel from your fuel system.

 

i had a similar problem...my boost only went up to 5 ..and it was couse i got hit by lightning and it fried the ECM ...but the turbo sensor was not showing any sing of damage...i replace it and the problem got fix...they go for about $100.00 dollars...

 

Fuel creates cylinder pressure which in turn creates exhaust pressure which powers the turbo to create boost for the air intake of the cylinder. When fuel is even slightly decreased all these things follow suit and also decrease causing low power. Don't be too quick to condemn the turbo before checking everything that makes it sing.