General Question Regarding Exhaust Fumes
 

hey there. so I have been working on a 1993 ranger stx 4.0l v6 4wd 5 speed manual. we figured out that the transmission is finished one gear is completely shredded off so we are getting a rebuilt one. any places to get one in Canada?

anyways. when we re-installed the transmission before we took the top hatch off we said "why not maybe it's just the clutch" we took out the cat-converters and straight piped it but left the muffler on. when we turned it over it sounded clean. its a very well running engine. no rattles no nothing. so my question is that whilst we were revving it up and trying to switch gears, the exhaust had a burning smell, it was kind of a greyish white smoke. not sure why. but it never did this at idle when we fired it up the other 3 times? any help would be greatly appreciated!

The computer runs the engine Rich every few seconds to keep the Cats hot, they get hot by burning unused fuel, this allows them to clean fuel and other chemicals out of the exhaust, so thats the grey smoke, since Cats are gone

When you burn gasoline(H) with air(O) one of the by products is H2O(water) this is why tail pipes drip water and exhaust systems rust from the inside out.

Without the Cat heat this water is condensing faster than before, the white smoke

The overall smell are the toxic gases that are now present because Cat hasn't cleaned them out

wow thank you for that info that's greatly appreciated!