Exhaust smell is not particularly helpful. I will note that CO has absolutely no smell which is why it is so effective at killing people with faulty furnaces. Your 1992 does not have the secondary O2 sensors that are associated with the OBDII system and monitor the condition of the catalytic converter. What is that 'rear O2 delete' all about since you never would have had a rear O2 sensor.
Have you deleted the catalytic converters? If so, that is likely the cause of your odours. EGR reduces NOx slightly; but, the majority of the NOx clean up occurs in the cat. High compression engines are particularly good at generating NOx and if the cat has been deleted or is dead it may be NOx that you are smelling - a particularly acrid eye watering stench. Everybody has forgotten (or not old enough to have experienced) what the air smelled like in the world of pre emission control vehicles.
The engine nominally operates at an air fuel ratio of 14.7 which in theory means no HC; but, the engine more accurately operates around 14.7 so relies on the cat to do the final clean up. HC does have smells; but, since the HCs are probably a bunch of different compounds and the smells vary. However, they are typically over whelmed by the stench of NOx on a high compression engine.
On a flyer, if you still have cats you could go get your tail pipe sniffed and that would tell you pretty quickly whether your cats are dead. If you have deleted the cats the car is going to stink and the people stuck in traffic behind you are going to be thinking 'what a piece of junk' and switching their AC to recirc mode.
