Hey guys,

I am trying to purchase my first aftermarket exhaust for my 2005 g35 coupe.
This guy at the dealership wants to sell me his HKS Legamax exhaust and piping, but he says it spits out fuel and won't pass smog so I'll have to switch back to my old exhaust for the smog.

Is this the case for most aftermarket exhausts, or is the one he is trying to sell me just not working properly?

What are some reasons a G35 will spit out fuel from just switching out the exhaust and piping?

 

If it's just the catback exhaust you should be fine. He most likely has test pipes also, So he pulled his cats. But either way if his is literally spitting fuel (liquid), he has serious engine problems... Most exhausts are catback or midpipe back so the cats stay intact and smog shouldn't be an issue

 

It's not fuel.. It's condensation.

 

Theres no way an exhaust would cause fuel to come out. Its more than likely water from the combustion making its way out of the exhaust.

 

So he probably doesn't have a cat on his exhaust setup then probably right?

 

It's elementary chemistry to know that the output of a combustion reaction is CO2, H2O and heat/light.

With proper working catalytic converters, toxic hydrocarbons and other monoxides have been removed, virtually reducing the exhaust to just heat, CO2, and H2O.

That's why engines "smoke" on cold mornings especially with the engine/exhaust being cold- the moisture in the exhaust hits the cold air and condenses.

 

If you want a cat-back and pass inspections i recommend keeping your stock cats. Just go for the y pipe, mid pipe, and muffler.