Mr2 Spyder 02 Sensors Replacement Tutorial 

No check engine light everything worked great and it's been over a year since I did them. If you have any other questions feel free to ask.

Yeah they are aftermarket and were on the car when I purchased it. I'm glad because I have read that the original headers that have the precats crumble over time and can more problems down the road. Best to replace them asap. The o2 sensors should still be close to the same spot as the original headers.