If you used any o2 sensor other that NTK (especially Bosch) they likely need to be replaced. Rockauto.com is the cheapest place to get them.I have 2005 TJ with a 4" lift. The check engine light comes on, (133, 153). I have replaced both O2 sencers but they keep coming back. However it did seem to go away during the winter. Any suggestions would be greatly appreciated.