I've got an 05 wrx I bought used about a year ago. Its got exactly 100k on the odo (I was commuting 180 miles a day for a while there). The only mod that was on it and still is is a BOV. Yesterday the Check Engine Light came on when I hit about 90, which I rarely do. After I got home I let the engine cool down, disconnected the negative battery terminal and the light went away. Now here's the problem: I drove it around for a little while after that an noticed that when I let off the accelerator, the noise from the BOV seems unusually loud. Also, acceleration doesn't feel the same. I stomped on it on third gear at about 30 miles per hour and the car took off, like I was in second. I know that isn't good. The CEL remained off for the remainder of the evening. My suspicion is something's wrong with the air/fuel ratio, maybe caused by the BOV, which I have planned on removing since I got the car but never got around to it. I kind of wish the CEL was still on so I can have diagnostic easlier ran on my car. Any ideas guys?