perrys4

When I start my car before a drive, the exhaust smells terrible. Will permiate the whole house in a matter of a few seconds. Smells way more than any other car I have had. What could cause this. It is not a gas smell. Just a strong exhaust smell.

T_MaX

Can you describe the smell?

I.e. Rotten egg, raw gas, burnt oil, or burnt coolant smell?

perrys4

I cant really nail it down. Just an exhaust smell but I dont notice it as bad when I restart it later in the day. Just seems to be when cold. Was thinking cat or o2 sensor since but dont know. Car was high on Nox at last testing.Dont know if that gives any clues.

T_MaX

Getting a good description of the smell would help greatly due to the fact all oils, fuel, coolant and running conditions have their own unique smell.

Is there any visible coloring of the exhaust gasses?

What brand of gas are you running? Is there any chance it is a bio-mix?

ErnestSw

The smell is probably from your catalytic converters. Someone has used leaded gas in the car resulting in the converters smelling and high Nox readings.

perrys4

Cant imagine where they would have gotten leaded gas. Was a one owner car and he was an enthusiast (owned five). I have had it for the last six years. I cant see that being the problem. I know the cats can go bad. I run premium Chevron only. Arent cat smells a rotten egg, sulfur smell?

ErnestSw

Yes they are, but it still sounds like a cat smell and the high Nox suggests a cat as well. If the smell is more like gasoline you may be running rich. That could be an O2 sensor. Ask your wife what it smells like.

T_MaX

If this was not happening when you’re bought it six years ago, than reg. gas won't be your problem. One simple thing to try would be changing fuel stations and brand of fuel at your next fill up. I have been reading some nasty things about some station operators as of late.

Some seem to be buying mixed fuels from questionable distributors.

Yes, the traditional smell of a bad cat is rotten egg smell.

SharkSkin

Maybe the Temp II sensor is calling for more enrichment than you actually need when cold?

Nicole

Cold cat = no cleaning

The RX-7 that I had in Germany did not have a cata but an exhaust recycling and burnign device (Inot sure how to better describe it). It was cleaner than other cars in therms or toxic emissions, but it smelled horribly.

Garth S

You may have an injector that doesn't seal correctly: this would leak raw fuel into a cylinder until the rail is depressurized - and create a rich start up ( unless left too long, so the fuel passes into the sump). Does the car start any differently when cold?

perrys4

Thinking back the now Ex-wife complained about the smell from the beginning. Car always starts with the first turn of the key and runs smooth. Is there a way to test it to see if it is running rich?

tv

When i first got my euro it had a bad exhaust smell. Not anything you could describe other than strong and unpleasant. It didn't have any cats. Now my second all new exhaust has metallic hi-flows and the exhaust smells like a mountain breeze.

Normy

When I'm driving behind other people, now and then I can smell a marked "rotten eggs" smell from their car. This means that they have just left the house or the office- the rotten egg smell comes strongest when the catalytic converter is cold. Another reason for strong smell is a rich mixture- you might want to have your O2 level checked and adjusted.

N!

perrys4

How does everyone feel about the Porsche o2 sensor @ $150.00 and the universal @$60.00?