ok hers my dilemma, i've got a 93 dx with a 96 ls swap, lately when i get on it around 5-6k i can smell a rich exhaust smell in cabin, tonight i just got a cel 43, i've haven't looked to much at the setup (i didnt' do the swap) but i think i've only got on o2 sensor (i'll look more tomorrow) but my question is would a bad o2 sensor be causing me to run rich thus the smell i get?

 

Code 43 "fuel supply system".. yes a bad o2 sensor will cause you to run rich, which can explain the exhaust smell inside the cabin. Any exhaust leaks which are letting fumes escape from directly under the cabin? Do you smell it when at a stop or also when cruising?

by the way if you are OBD1 you only need a primary o2 sensor, not a secondary after the cat. Replace your primary o2 and see if that clears the code.

 

well it did have some leaks but they were around the last bend by the axle. and i smell it for about 5 mins after i get on it stopped and not. but i think it was converted to obd2 i'm gonna check it up and down today and get back.