Stinky exhaust smell

lexus
gs400

#1

Hi everyone! My 2000 GS 400 has what I like to call an ‘old car’ stinky exhaust smell while running. I would like to get rid of the smell as it is annoying. Does anyone have any advice on what I can look for/replace to alleviate this problem?
FYI, The CEL came on for some evap/emission codes a couple of months ago and I found two broken hoses under the hood which I replaced and the codes went away. The CEL has not come on since.

Thanks in advance for the help!


#2

What do you mean by stinky exhaust smell, gas, rotten eggs?


#3

If it smells like rotten eggs, that usually indicates a problem with the catalytic converter not working efficiently.

What exactly is the smell??


#4

Well, it’s not rotten eggs. Mostly smells of gas. Have you guys never been behind an old pickup truck or car on the highway and you can just smell them killing the ozone layer? It’s similar to that, but on a smaller scale.


#5

Is there any smoke associated with the smell?


#6

I’ve noticed a small amount of smoke when cranking the car after it has been sitting a while. Usually overnight. The longer it sits the little bit more smoke. It’s does have 228k miles, but still runs like a top.


#7

The smell may be oil burning. Probably worn valve seats that lets a little oil pass through. If the engine has been sitting long enough then the oil will collect on top of the cylinder head. Then when you start the car it burns off the accumulated oil. It does smell.

But it’s extremely difficult to diagnose a smell over the internet. I suggest you take it to a trusted mechanic. Anything we say is purely a guess.


#8

It might also be a leaky injector or even a fuel leak. I’d recommend getting it checked out by a reputable shop.


#9

Good ideas above. Another idea, you may have a small leak in your exhaust system up front enough that it’s causing some exhaust gas to go into the passenger compartment and you’re noticing the odor. Any good shop can check for that and decide one way or another, doesn’t take much time. Sometimes you can check yourself when starting on cold morning, you’ll see white steam out the end of the tailpipe which is normal, and a little white steam coming out under the car, which is not normal and indicates an exhaust leak. This effect can be accentuated if you – for testing purposes only – hold a piece of wood, like a 2 x 4, across the end of the tailpipe to partially obstruct the flow.


#10

Bring the vehicle to a shop and explain that you smell what seems to be exhaust gasses.

They’ll put it on a lift, start the engine, and block off the tail pipe(s) to see if there’s any leaks in the exhaust system.

Tester


#11

Thanks everyone for the replies. I will have to take it to a shop and see what they say.