There should be one in the header and one more in the catalytic converter.
oxygen sensors are located just forward of your engine. In front of the engine is the catalytic converter. At the top at the bottom are your oxygen sensors.
All O2 sensors are located somewhere on the exhaust system.
1993 Honda Civic EX's dont have knock sensors.
There is one and it is before the catalytic converter.
It is located on the header.
Check
2 ... one on top and one underneath the exhaust header
how many coolant sensors do i have on a 2003 civic si ep3
in the catalyc converter... exhaust manifold
there are five sensors on a Honda civic intake three are on the passenger side top the others are on the middle and drivers side of the bottom
The oxygen sensors on all vehicles are uasually located before and after the catalitic converter to monitor your emisions ! Good Luck !
probably one located just after the engine on the exhaust. by now this sensor will be stuffed