I finally got my boost gauge installed and was dissapointed that my boost would peak at 15 psi. I took it to the dealer and they found the problem. They showed me a Mitsu newsletter that addressed it.

Here is exactly what it says:

"LACK OF TURBO BOOST -- 2003 Lancer Evolution: If you receive a customer complaint of lack of power and/or lack or turbo boost, it may be due to a problem with the operation of the wastegate actuator solenoid. When energized, this solenoid should open to allow pressure to bleed from the wastegate system. If the solenoid doesn't do this, maximum boost cannot be achieved."

I've seen many discussions about "not enough boost" and "under-powered Evos" with varying reasons about why that may be and many possible "fixes" so I thought I'd share this info.

My advice: If you are experiencing lack of power and/or boost, take it to the dealer first so that they can rule out the issue above as the problem before trying any other remedies.

 

I was home for 2 weeks in the begining of dec on leave from iraq my evo ran great for a week or so and one day it lost power to me it felt like a vacume leak or wastegate opening when it shouldnt i also noticed a change in exhaust note witch made me think it had to do with either the wastegate or the variable backpresure valve thank you for your post it has helped me greatly




oh and the first week i was home i beat my friends brand new sti and the second week i got beaten by a 02 wrx not good