stink butt

[Butterfinger]

I had an 89' without cats on it and it smelled bad of fuel from behind (engine was not buring any oil), do all Mustangs without cats stink or was it just that car? (everything else on the engine was stock)

 

[Mustang5L5]

Pretty much every mustang i've been around without cats smells from the exhaust.

Kinda why i run cats

 

[LarsD]

Unless you are running rich, that's what a hot rod smells like.

 

[dagenham]

I cant say that I have ever noticed any smell from the back of the wife's car and it doesnt have cats.

 

[Butterfinger]

So the smell comes from a bad tune and no cats? The two O2 sensors are before the pre cats, so I don't see how the EEC-IV would ever know if the cats were removed, so where does the bad smell of gas come from?

 

[Mustang5L5]

What you are smelling is unbunrt hydrocarbons which smell like raw fuel. It's not an indicator of poor tune.

The cat converters use various compounds to turn hydrocarbons, co and nox into co2 and water vapor.

Eliminate the cats, and instead of neutral smelling co2 and water vapor coming out of the exhaust, you smell hydrocarbons.

 

[striker911]

My car has not had cats for the 8 years I have had it. I remember when I first got it I helped a friend haul a grill and the hatch would not close. It was real smelly in the car and we had to keep the windows down. That was when it was stock like yours. It has a lot of upgrades now and is still that way. If I pull up next to a car that has the windows down they end up rolling them up lol. Honest I hate it.

I like loud cars though and if I put cats on it I am sure to hate it. Had a leak fixed in the system and that alone made it a lot more quieter. I miss the hole in the pipe. I wonder what it would sound like with no mufflers and some high flow cats? Anyone ever hear that set up? I have some old flow masters (10 years +) as of now.

 

[stykthyn]

Run that set up on my truck. Its loud.