Recently, I've noticed a strong smell of gasoline emanating from the rear driver side tire area and exhaust pipes when I shut my car off after driving. I've been checking under it each time before I start it, as well as checking after I park anywhere, to see if it is leaking or dripping any fluids; other than a few drops of transmission fluid, there's been nothing. The smell always dissipates a few minutes after shutting the engine off, but it's not 'normal'. I can't find anything unusual under the hood, either. I do keep track of my average gas mileage with each filling of the tank (around 25-27 mpg when the weather/driving conditions are nice, 22-24 mpg when it's colder/lots of heavy traffic...lately, it's been around 20-22 mpg. I don't know if that's significant or not, since I have been doing more in-town 'start and stop' driving than usual). For what it's worth, about a month ago, my fuel pump died and was replaced with a stock pump. I also had to replace my fuel filter. Is it possible I've got a leak somewhere that I just can't see? I've also heard that sometimes gas can get into the exhaust system; is that true? If so, how does it happen and how can I check to see if that's what it is?

Not sure how much of this info will be useful, but:

I've got a 1990 Camaro RS, 305 TBI; engine and exhaust are both stock. The exhaust is fairly new (only about 10,000 miles on it).

 

It sounds like you have a pinhole leak in your filler neck. When your car is running it builds up pressure and forces the vapor to be vented into your quarter panel area, it's pretty well closed off in there.

I had the same thing happen to me, people told me to take it in to Chevy and have them do something about it... I simply kept driving it until I was out of gas, then I dropped the tank and fixed the hole with JB weld.

I'd still bet 50 bucks it was less hassle than getting Chevy to do something about it.

 

Well then, you have a leak that's not apparent.

Smell = leak. Pretty easy to figure out.

Probably one of the lines going to the tank isn't tight or is broken or something, on top of the tank; or, the tank filler neck got cracked during the R&R.

 

so how did you fix the pin hole leak? what tools or materials were needed?

 

if you do have a small hole in the tank, you can buy some stuff designed for repairing pin holes in the gas tank. follow the instructions & it should work just fine.

http://www.permatex.com/products/aut...ank_Repair.htm