'oo gsr, i did the ebay thing, the same way ever tuners horror story begins...
i bought an obx high flow cat. of course, 63k on the car, the stock cat was a bitch to get out. i noticed the o2 sensor was in a different place, in front of the cat instead of at the other end. i figure im going to get a CEL either way, so i put it in. my luck, they must have shortened or lengthened the tubing somewhere along the line, the o2 sensor was in contact with the chassis. it was late oclock at this point so i had to drive it home the way it was. ive since unplugged the o2 and put a plug in to lose the vibration shooting from the motor all the way to my steering wheel. the car definitely shows improvement, but theres gotta be a catch other than that stomach turning lil yellow light i now have glaring at me everytime i start the car. what are the consequences based on stories experiences or any other knowledge of the secondary o2 sensors? mpg? performance? please let me know what you think...