It's not quite as you picture this, you are describing compression in the combustion chamber. Boost is created by turbo which is fed by exhaust gas, a by product of combustion. You'd be boosting low because stuck open egr valve will rob your turbos from precious exhaust gases and the exhaust gases are the force that spins turbine. Lower exhaust gas pressure has direct effect on how fast your turbine and your compressor wheel spins thus produce boost, it will essentially act as a waste gate on your turbos. Just imagine pumping a tire to a desired pressure while having big hole in it.
As painful as it is now, it'll save you money and aggravation later later. If it helps or maybe discourage you (you make the call) but those are the items I'd take care of if I'd in your shoes (assuming it never been touched before) #1 Egr valve $1000-$1200 (I managed to get genuine one from ebay for $650, I may have a phone number to a guy I bought it from as he's local to me) * M1M Aftermarket Egr hot side cooler core $720 shipped (they're being made next town to where I live) * I'd do OEM Egr cold side cooler core ~$500 too #2 Doser valve replacement about ~$450 or good cleaning $0 but that depends on how many miles you have on the unit, if over 300k than replace with new one. #3 Both crossover exhaust manifold to Egr pipes. I got genuine OEM on ebay for under $150 shipped #4 O2 sensor, don't know the price but if it's less than $200 I'd replace it. Remember, you can't reuse old one once removed. You'll need some gaskets and hot side egr core puller tool which you maybe able to rent from the dealer hopefully or a shop that specializes in servicing Internationals. Otherwise this stupid tool will cost you upward of $1500 to $2000. In the end you'll need to use this tool only once for removal process as long you are installing M1M core this tool is not required to put the core back in. Cold side cooler core can be prayed out without special tools. Use YouTube.com for video reference. If you're not planning on doing this yourself than add many shop labor hours( 20-25? at $100/hr that's a lot of parts money. If you know how to wrench you can do it yourself, the only obstacle in my opinion would be egr cooler core puller tool, other than that it can be done with regular tools. If you have more questions, let me know
I have pulled out the hot side egr cooler without the expensive tool. Since buying the M1M, which doesn't need the tool to put back in. I put a 4x4 behind both seats and attached a come along to that. I then screwed a large 2x6 board to the egr cooler with a BUNCH of screws and some bolts. It came out "easily ". At least didn't buy a very expensive part for 1 use.
