Well, to start off, I'm new to the forums.. I have however been reading them for the 2 years that I have had my subie, and the great diagnosticians here have probably saved me upwards of 4k in repairs by figuring it out myself, and conducting my own repairs.. Unfortunately now, I am in need of some serious help.
The car is an 03 bugeye wrx wagon, some mods I know about, some I dont as i bought it used a few years ago. I have put a spectra short ram, sti tmic, forge bov, samco hose kit, new maf, apexi 3" catless exaust, and recently changed nearly every vacuum line in the entire car.
The car used to run perfectly, pulled extremely hard, about 1.7 bars of boost, steady idle, zero problems, may have well been brand new. Then I deployed for a year to iraq, with the car left to my wife's vices, and returned to a much different machine then when I left.
The problem started a few months ago, the battery in the car had gone dead from it sitting while the wife was on vacation for a few weeks, she returned, replaced the battery, and as far as i can tell this started a downfall of nightmarish problems.
First the car lost the ability to idle on its own, she took it to a shop here, and they said it was the IACV, replaced it, same problem, she took it back, they replaced the bov with the stock recirc and said that should fix it. The car eventually seemed to fix its own idle issue, but the recirc had nothing to do with the problem. Then i returned. I jumped in the car and started to drive like usual (I.E. Like a bat out of hell) went to WOT and BAM, Hard stutter under boost, maybe hit one bar, and then just shook the car to hell. Researched on your forums, and found it may be fuel cut, No CEL, and didnt seem to match all symptoms because the car began having trouble accelerating under any boost at all.
I began thinking that it was possibly a vac leak somewhere around the engine compartment (The biggest problems are usually the smallest things, right?) so i got some carb cleaner and started spraying around every vac connection in the engine bay listening for a change in the idle.. nothing, but i figured it would cost me about 12 bucks, and new vac lines couldnt hurt anything, so i replaced them all anyway.
Then i heard it could be boost leak or boost creep, I've been told that boost leak is usually very loud, so it seemed unlikely because the car isnt making any unusual sounds, and boost creep could cause me to hit fuel cut, but now the car isnt cutting fuel, its just not accelerating AT ALL. The car runs fine until there is any load on the engine. If im driving and i can keep the boost press in the negatives, it seems like its perfect, but the second i hit a small incline and the car goes over 0 bar it will quickly jump to .5 bar and loose all power. the engine stays running, but it will not accelerate until i drop the revs and get the boost back under 0. there doesnt seem to be any real misfire, but i have noticed now that when i downshift into second i am much more likely to get a backfire, this however is not setting off a CEL either. I have checked the restrictor pill, its still there, and i tried putting the car into diagnostic mode to see if i could hear a click, but no dice, I have heard mixed messages about weather this actually will cause it to click or not.
I LOVE my car, and it is making me severely depressed to watch it sit in my driveway day after day as i drive my wifes mitsubishi to work everyday. Any help, suggestions or things i havent tried are welcome. Im desperate, I would sever my wrist and pour blood into the throttle body if someone told me it would work at this point. There some automotive geniuses on this site, some come on outta the woodwork, and lemme know what stupid thing i have missed thats gonna fix my baby ;-)
Thanks again everyone, and im hoping the solution comes out of this!