[ChevyTech]

In 1993 the oxygen sensor is in the divers side exhaust manifold, near the flange.

If the oxygen sensor is not connected it should set a trouble code. Make sure the light comes on when you turn the key before cranking the engine. Somebody may have put in a custom chip that is preventing a code from being set.

To set the code 32 the system cuts the EGR operation under specific criteria and watches the oxygen sensor expecting a change which meets a threshold.

A vehicle without an oxygen sensor will run in the “Open Loop” mode and will get an amount of fuel that is in the program in the PROM(chip) that is what should be adequate if the other sensors are working OK and everything is about where it should be.

You will not get the best fuel economy or performance running in open loop with no oxygen sensor connected to the system.