So I have an 04 with 66k on the chassis and 20k on the new engine. About 3 or 4k miles ago I noticed a power loss below 4,000 RPM. It came and went but just recently it became a non stop issue. And when I say power loss, the car goes the same under 4k Rpm whether i'm pushing 10% on the pedal as it does when i'm pushing 100%. The car finally starts to go around 4500 Rpm. After taking it to the dealer last week, i told the mechanic about the problem, got a 60 thousand mile service done, and a carbon flush. He told me the carbon flush didn't do anything for the loss. He recommended I bring it back for a diagnostic. I had a 2hr trip to make that day and I have to admit I don't redline the car as much as I should, and figured i'd redline it a couple times in different gears. The CEL came on right after I left the dealer and then turned off about 20 miles later. I called the mechanic and he said it had come on during his test drive and the code was for the Intake manifold. I kept that in mind and while redlining through 3rd gear, the car didn't want to go after 8k rpm, it stuttered and jumped and made me nervous, so I slowed way down. then dropped back down to 2nd and it stuttered through the powerband after 4k rpms. As far as the idle issue goes, it just misfires constantly while idling. In one instance it dropped down to 750 rpm two or three times and almost died. that was on the same trip.

So after reading and searching I'm assuming a couple things but really need help.
1. Rough idle could be due to coils. They need to be changed...
2. I'm thinking the SSV might be stuck. I've read about the process of getting it moving again, and am thinking about doing it around christmas, which will be the next time the car comes out of Winter storage, since I live in Boston during the year.

Any advice/suggestions would be awesome. I trust my local dealer to a minimal level, because the mechanic and service advisor team that worked on my car up to about 47k miles became friends of mine and are no longer there. Now, I don't know the new mechanic that well, as the old one moved to a different dealer. I don't want to go in there and them try to charge me $1000 for a new intake manifold and labor when it might not even fix the problem. So i know that you guys are here to help!

 

Get the code read to verify whether its the SSV. If not try coils first.