andynoel78

Hi all:

I have a 2003 SC430 with 170,000 miles on the odo. It runs great, but the exhaust smell is killing me. I'm pretty sure it's normal for an 11 year old car, but i want to eliminate it.

Do you know what part or part(s) i might be able to replace to eliminate the foul smell?

Thanks in advance!

LexBrett

Is that normal? My car is 12 years old and I don't smell any exhaust whatsoever. Could something be wrong with your emissions, like a bad 02 sensor? Have you tried a fuel system cleaner such as Lucas or Seafoam?

andynoel78

Thanks for the reply!

I believe the odor (and the extent) that i'm smelling is normal for its age, but i'd like to eliminate it. I'm assuming some part (or parts) are starting to fail, but i don't know what.

I've only had the car for 2 months, and the odor has stayed the same. I've used 93 octane, exclusively. No check engine lights on.

I haven't tried any fuel cleaners, yet. How can i determine if the O2 sensors are the culprit?

ShawnOk

iTrader: (1)

Never had any exhaust smell with my 02.

LexBrett

I'd start with Lucas Fuel Deep Fuel System Treatment (in the blue bottle) or Seafoam in your gas tank.

If your fuel injectors and fuel system has never been cleaned, you will definitely get peppier acceleration. So even if these products don't reduce your emissions smell, I can almost guarantee they will help car's performance and MPG. Especially with a car with that many miles.

I recently read several automotive repair books that suggest oxygen sensors degrade over time and need to be replaced periodically, which could effect emissions, although opinions vary on this subject and I'm no expert.

Maybe someone else will chime in and can give you some suggestions..

dustoff44

iTrader: (1)

Probably the catalytic converter. It will only clean s much exhaust until the element is spent. IMHO

bb430

iTrader: (1)

I agree. For the most part, cat. converters work till about 100k miles or so.

FLYCT

+1 sure sounds like a bad cat.

Harold57

If it smells like sulfur (or rotten eggs), it is the cat.

SC43052

Cats or exhaust leak.
Listen for ticking noise which would suggest an exhaust manifold leak, especially if it gets louder when accelerating.

andynoel78

Thanks again for the replies!

I do not hear any ticking or see any indications of an exhaust leak.

For the last two "fill-ups" i added the "Lucas Fuel Deep Fuel System" cleaner. I actually DO notice several improvements!! The exhaust smell has decreased, in a way. The odor is more faint, and it smells "different." Hard to describe. I've also noticed a decrease in "idle vibration" (i actually started another thread on here regarding that, too).

Should i continue to add the Lucas cleaner for the next few fill-ups? Does the noticeable decrease in odor mean that my catalytic converters are OK? And does the SC have TWO cats or just one?

Carlos Ramirez

The smell you are talking about is most likely an exhaust leak. You probably have a blown exhaust header gasket. Or you have a leaking valve cover and the exhaust smell is a burning oil smell instead. Take it to a shop and they will be able to find fairly easily if they have experience in this issue.

The idea of adding fuel cleaners and etc is not a bad one but it won't get rid of the smells, if you have an exhaust or oil leak.

Bgw70

Hey Andy!
The SC430 has two cats.
BTW, do you reside in SV, Fl?

Caseoane

Does it smell bad out of both mufflers or only one? Test it - if it's only one it's probably the material inside the muffler that's gone wrong, or detached itself. There is stuff there to scrub the gas as it comes out.

sorka

My SC400 pass CA emissions with practically zero CO, NOx, and HCs at 333K miles with the original cats. I also didn't have any sort of exhaust smell. I don't believe that's normal for any mileage. Do you really want risk your health?