when i put my catless downpipe/cutout on... i never got a chance to put this little o2 spacer/breather on the back o2 sensor so i just plugged the rear one in. I drove around for maybe about a week(getting about 12-13 psi on stock tune at WOT) until the check engine light came on. I rode around for probably another week, thinking the CEL was for the rear o2 sensor realizing there's no cat. after a while, I wasn't hitting the usual 12 psi I was getting when i first installed the pipe... I would only get half of that, and it would get there slow as hell. I kinda chalked it up to the tcv finally blowing.<p>so yesterday I decided to put that little o2 spacer in and erased the code with the code reader(I was stupid and didn't take note of what code I actually had since I thought I already knew what the CEL was for). Immedatly after starting the car, the car idled at around 1k for like maybe 10 seconds and then leveled out. For some reason I thought I was supposed to drive like a granny so I can give the ecu a chance to adapt after clearing the codes, so that's exactly what I did that night and alittle the next morning... but I did get a chance to do a WOT pull from 2nd to 4th gear and full boost was back and felt like a completely different car. <p>after driving for maybe about 80 -90 miles after clearing the code the night before... the CEL comes back on. got it read by nicky and got took note of the two CEL's... front o2 sensor high signal and fuel trim CEL(im assuming the second is a result from the first one). I erased the codes... the car kinda idled high for a bit(just like it did the night before when I erased the codes) and nicky told me to drive WOT everywhere... and that's what I did. I got full boost back the whole afternoon till just now what I finally got home.<p>was i in a reduced state of boost just cuz of a god damn o2 sensor? is the s60r tcv that I ordered kinda pointless at this point? and is my o2 sensor up front shot? <p>I would appreciate any help at all.