My car smells like gas when I turn the engine off. The smell is NOT in my car but smells up the garage

Hi Ed.
this is all i could find at the moment.
Gas Cap Causing Gasoline Smell in Car. I know it may seem obvious, but a loose or missing gas cap can cause a fuel smell in your vehicle. You could even have a faulty gas cap that is leaking fumes. A faulty gas cap can also cause the check engine light to illuminate with a DTC on newer cars.

Gasoline Smell in Car, 5 Common Causes - Simple Car Answers

or go to this link and read up some more.
Smelled gas and check engine light came on Google Search

Yes, if the gas smell comes from the engine compartment.

First advice: do not park the car in the garage until you've found the cause of the smell and fixed the leak. It takes very little gasoline vapour in a confined space to form an explosive mixture which could be detonated by a small static spark.

Do not start or use Vehicle. If in Garage, do not use the garage door opener. Manually open the door to Garage. Call tow truck with a flatbed. Have vehicle towed to open location.

There were some vehicles with Recalled gas tank straps. But anything could be wrong. The fix may be reasonable.

Call a Dealer with your Vin# to see if yours is an affected Recall.

check garage for gas can first.

ask cadillac if they checked the charcoal canister

I would check the gas cap to make sure the gasket is seating correctly on the filler neck. Also check, if you can, the filler neck from the gas cap down to the tank. If it is damaged, it could seep gas fumes. If you see no other signs of an obvious leak on the garage floor, it's likely a gasket issue in the fuel fill side of the system. It does not take much fumes to smell it strongly.

your car may not be burning off all the fuel or you are leaking. just because you dont see it on the floor doesnt mean that your not leaking. because its hot under there your evaporating faster than you drip. check your lines starting at tank. check under hood where it connects to injection system.
run the engine and smell exhaust for fuel. put your hand at the tip while engine is cold running. if you get fuel go get a tune up. if smell it while driving you have a leak. i would need more info on the car. like has it been running a little less normal?

you HAVE a gas leak, the best way for this problem is to use your senses of smell and sight.
Look for gas leaking at the same time smell for the strong smell of gas and locate the area.

I recently had the same problem. It turned out that the fuel regulator on the engine at the left side just above the intake manifold had an intermitent leak. The gas leaking was not always visible so I had the regulator changed and that solved the problem.

Change your fuel filter