I guess im going to have to give it a try I'll let you know the results tomarrow. Not sure what else to do. I know there arent any leaks or mech problems. I dont know if all 02's are the same. If you have ever measured the temp at the manifold on most Vehicles are about 180 and the cat runs about 3-400. So I would think the heater would be different. My Headers are not coated but wraped so mabey this has somthing to do with it.