[jrformerlys]

My Saab 9-3 was in a rear end accident with extensive body damage. After the accident the exhaust was smoking heavily. I had a new Turbo put in, an O2 sensor replaced. Insurance said it was not accident related. 366 miles after repair service engine light went on. Dealership could not find a problem although code indicated evaporation leak. Two days later the car stopped when I was driving...just stopped. Any thoughts on whether evaporation leak could cause this and whether a rear end colision could cause evaporation leak?

 

[michaLcoughliN]

well whoever is doing the test for that evap leak doesnt know what they are doing if they cant find it. Normally they test evap leaks with smoke.

I had a big problem with an evap leak ongoing with my dealer. First it was a return valve that sits above the gas tank. Total damage $400 labour / parts.

Then it came back on again, they did another smoke test. This time it was the Oring for my fuel pump (fuek pump is seated on the top of the tank)

So they replaced the Oring and i got 50% off due to trial and error of not noticing it the first time.

So Your best bet is to get a smoke test done. And sorry about your luck. And the smoke coming out of the exhaust is normally indiciation of the turbo. Ide double check that, and if needed, you can replace that yourself. If you are handy that is

 

[3rd stone from the sun]

Do you know what those trouble code(s) were?
If you're 'lucky' enough, you get a generic trouble code and also a second, more specific code, indicating the source of the leak.

The evaporative emission system includes the fuel tank, the EVAP vent solenoid, the fuel tank pressure sensor, the fuel pipes and hoses, the fuel vapor lines, the fuel cap, the EVAP canister, the purge lines, the EVAP canister purge valve and probably more components I can't think of right now.
Given the severity of the crash, it's possible that any of those system components may have been affected, e.g. a disconnected or damaged EVAP purge line, a cracked EVAP cannister or a damaged cannister purge valve.
And yes, a smoke test machine with a flow gauge would most likeky verify the evap leak.