Exhaust in the cabin
 

I am experiencing an issue which is confounding me and my local Porsche-centric indy. I am frustrated, really hoping the collective wisdom and problem solving of this group can solve the mystery.

The problem: Extremely strong exhaust smell in the cabin, even with the top down. It is so strong I cannot drive the car. After driving and parking the car the smell is very strong near the air intake vents. There is no smell at the exhaust tips. It is possible the smell is not exhaust but something else burning.

Background: I've had the car for 4.5 years. The issue started after the catalytic converters were replaced several months ago. I returned the car to the indy and he thoroughly inspected the car after i encountered the exhaust in the cabin. He found nothing from replacing the cats that would have caused this. Another variable which may or may not be a contributing factor, around the same time the cats were replaced the oil was changed and the oil level was to the max. I was concerned that this may have been the cause. My indy checked the AOS and said it was fine.

I will be grateful for any insights

I don't know how exhaust could get in the cabin, but in addition to the smell, have you had any headaches or disorientation while driving? Before driving any more you might want to see what is available in the way of portable carbon monoxide detectors to take in the car with you.

If you bring me the car I'll give it a smell test. Might be something getting too hot.

I'll bet some PS or oil leak.

Thanks. Doesn't smell like burning oil. No idea what burning PS smells like.

The only way exhaust could get into the cabin would be if either engine cover were not tight and sealed.

Or if the car were a Corvair:D

The good thing about a scent is that it can be tracked down...

Does the odor occur while the car is stationary or when its moving? Or both?

You say that there is no odor from the exhaust tips yet there is a strong smell in the interior. Remove the engine cover to see if that re-creates the odor? If so, the engine cover may not be sealing properly.

Do the same for the front engine cover behind the seats? Same odor when removed? Might not be sealing properly.

Lay on the ground next to the car by the doors when the engine is idling - any odor? Might be an exhaust leak from the exhaust manifold or exhaust system.

A little detective work should be able to identify the source.

Thank you for your thoughts and comments. Sorry for the delay, life and work...So, I have some interesting updates. The fumes were stronger on the driver's side than passenger in the cabin. But, the fumes were nonexistent on the driver's side intake and tailpipes. Extremely strong at the passenger's side intake. While on the way back to the indy it threw a CEL with a ton of codes. Indy opened the top of the engine to discover that there had been a fire. In retrospect, i can tell you when the fire occurred. It was a week or two before i originally posted. The fumes were present for months and several hours of drive time prior to the fire. I do not think the fire was the cause of the fumes. I believe the source of the fumes may point to what caused the fire.
Has anyone heard of a Boxster catching on fire in this manner? Any thoughts on the cause?

What was it that caught fire? Mouse nest? Oil drip? Gasoline leak?