oxygen sensor wire behind heat shield - JeepForum Mar 03, 2013oxygen sensor wire behind heat shield I'm about to replace 2/2 and noticed that the wire is under a heatshield. I'm mot quite sure how I should go about this. Should I unbolt it which are the bolts for oil pan I believe.Author: Thetexan13 O2 sensors for the Jeep Wrangler. How to test if they are To test the heater part all you need is a multi-meter. With the sensor at room temp around 77 degrees F (25 degrees C). Put the both red and black lead across the white wires. Resistance should read between 5 and 7 ohms between the two wires.