LS430Lexus

I noticed a strong exhaust (like diesel exhaust smell) inside the car yesterday. It mostly went away in a minute or two, figured it was from another vehicle on the road. Today, I noticed a little exhaust smell in the back of the car when I pulled into the garage today after driving home (a mile or two) through fresh snow.

In the back of my head, I'm thinking catalytic converters or other exhaust issues on my '06 LS430 ML with about 95k. After 20 years of Lexus privilege and pleasurable driving over 4 different LS's, this would potentially be my first exhaust related issue. Any ideas?

BigBoomer

More likely to be an oil leak somewhere that is dripping onto the exhaust.
The CATs on these are good for 300k+ miles and even when they do go you will get error codes thrown when they begin to get marginal.

aypues

I think that might've been when I did my valve covers. They were leaking slowly onto something hot below it and made an awful smell that got worse over time, to the point where you could see smoke coming out of the engine bay.

LS430Lexus

Valve covers or an oil leak may make some sense. How big a job is replacing valve covers? I usually provide the parts and a trusted Toyota dealer does the work. The timing belt was replaced 5 years ago at about 45k. Car now has about 95k and I was thinking of changing the spark plugs at 100k.

Bocatrip

Valve cover gasket leaks are quite common. The driver's side is not too bad but the passenger side is more of a pain. It's important to note that if you are DIY that when replacing the cover with the gasket attached to it, to be careful not to pinch the gasket when reinstalling. This often will cause leaks after the replacement. I replaced my plugs about 121,000 miles and the old ones didn't look that bad.