Anybody noticed huge gasoline smell from exhaust during a cold start? Smells like a 10 yrs old car for about a minute for me. Not sure if this is normal?

Thanks

 

Mine doesn't. How many miles are on your car?

 

Only 3k miles

 

Does this happen on every cold start?

What is your tank's fuel level when this occurs?

Does this happen in warm weather or cold?

Which trim package? Turbo? F-Sport, or hybrid?

What gasoline octane are use using?

 

I was always taught that catalytic converters take about 30s to start working so regardless of whether the car is new or old, you will always get more fuel smell right at start up.

 

A cat doesn't start "working" at all. It's a metal drum with various filters.

You are not smelling gas would be my assumption, but rather raw exhaust. This happens on all cars, new and old. It has to do with how the engine is tuned.

When cold, the engine starts and just dumps as much fuel as possible into the car as it attempts to heat up as much as possible. It ignores emissions and the output from the rear O2. This is the raw exhaust. As the car warms up, and the thermostat takes over temperature controls, it begins to monitor the rear o2 sensor as the cat is now up to temperature and the filters inside it should now be working and the smell should be gone.

I am really starting to believe that high schools should offer some sort of internal combustion class. Maybe as part of chemistry? There are too many people that just think they put gas in, some magic happens, and the car moves.

 

Pretty much full tank.
About 7-9degrees.
F sport package
91 shell only

 

I don't think it matters as my mazdaspeed3 2011 doesn't even smell like that at cold start and also my 06 rav4 is even better.

 

I got this once a few days ago when I had to move the car before my girlfriend could get in because I parked very close to a wall. It was also really cold (-10C) so I put the car into drive as soon as the car started so that I could move the car forward a few meters to let her in. After we noticed the gas smell.

The tank was full and I immediately put the car in gear.
This is the only time we've noticed it. Otherwise, cold starts after waiting for around 30 seconds does not seem to cause it.

Ideas?

 

At cold start vs warm the ECU works in two different modes open vs closed loop. As Swacer stated simplistically the ecu dumps loads of fuel based on programming parameters to get the vehicle operating temp so the cats are able to work in an optimium range. Running rich is usually how it works, plus holding lower gears longer.

Anyways no one can tell you whats the deal about your exhaust besides a trouble code if that exists so Dealership. If you are really good at fuel trims and OBD software readers, then figure out whether the vehicle fuel trims and modes are operating within parameters. Thats basically the best anyone can say and what a good mechanic would, but without a trouble code the cars probs fine

 

07 IS350
I notice the smell on cold starts too. It is intense smell of exhaust. I suspect exhaust leak? I smell the same thing on hard accelerations too.

This is not normal, my car was not doing that.