Hi Jim. About the overboost cutout switch, it's located under the dash above the kickpanel that has the pedal runs in it. It's at the other end of the vacuum line that you probably T'd into in order to get your autometer gauge to recieve boost pressure. It's hard to describe, so just follow the vaccuum line that goes from the dash gauge, to the area next to the ECU, it'll go to a circular "thing" with a bit of black epoxy on it, and another hose leading to the firewall and eventually to the intake manifold, where it measures the boost pressure. It is factory set to 13.7psi (hence reason for my conservative 12psi, incase of overswing on a colder day). Do you have the Turbo + system by any chance? That comes with a modified switch that's set for 15psi.

Your turbo is a Mitsubishi TD04, a smaller unit (when compared to the Garrett AIReasearch T3 or TD05 found in older gen. turbos) made for faster spoolup times for increased low end power, but quickly runs out of steam at higher boost levels.

Also, there's a post in this thread about CAI's and whatnot. I'm sure the maker of the CAI doesn't want to hear this, but Volvo's stock airbox has a pretty effective cold air inlet that goes from the pass. side fender into the airbox. If you look inside your airbox, there's a whole bunch of crap in there you can remove, such as foam, some random shrouds and most importantly, the trumpet shaped restrictor placed inside the tube leading to the fender. This will free up airflow by at least 35%. 35%, however, doesn't mean an increase in HP, just an increase in airflow going into the box. IMHO the AMM is the bottleneck in the system, and all CAI's hook onto that.

Also, with regards to the factory airbox, a few people have punched out the little "cutout" behind the pass. side headlight (made for the euro model headlight wiper motor) and placed a cold air pickup tube in there and routed it to a hole (you've gotta make it) in the front of the stock airbox. That's what I've got running. No discernable increase in HP, but it amplifies the sound of the intake nicely.

If you're suspecting your K&N of sucking in rocks and dirt and goats and spears and small children, remove the AMM and look into the hose that leads from the AMM to the turbo's compressor. Look for particulate matter where the hose that comes from the oil trap (drivers side) meets said inlet hose. If you find something that's not to your liking, AMSOil stocks a quality filter, so does that place everyone hates to go... the dealer.

Also, drain the Intercooler. There's a plastic (be careful, it strips REAL easy) drain plug on the drivers side on the bottom of the IC. This can be done with the intercooler in the car, but if you want to take it out, it's really easy to do. 'Bout the time that I drained <5 cups of oil sludge from my intercooler per week, was 'bout the time my turbo with 150k on it started to dislike the notion of 12psi, and has been slowly bleeding off boost ever since. Right now I'm at 4.5 psi desperately awaiting a cash infusion (paycheck) to cover the projected T3/T4 conversion...

Hope that helps, again, sorry for the long post.

Ryan