So my question for you guys is this. I recently changed my headers to an after market one. Once i was done I noticed that there was no hole for the O2 sensor. So without running the car I put the stock ones back on. When I startd the car there was a little popping then it went away. I went to drive it and the car idles completly smooth. Once I floor the gas the car falls on itself. Does anyone have a clue what could cause this to happen? Thank you very much....