Idle problem and jerking?

I had the same jerking prob and all that happened and that was because i did not put the downstreamtube back to the air pump for the cats but i have no cats so i left it off and someone told me that it should be put back on. Since having an off road pipe my o2 sensors were shot and check engine light would come on and engine wont performe at low speeds, so i bought some new sensors and havent had the problem since. So if you have an off road pipe then try that and see what happens.