car starts and runs 2 seconds
 

I have been reading through these forums for days. My moms 2007 S80 won't stay running. I changed the battery a few days ago and before that it was running fine. Since then when I start the car it runs for about two seconds and shuts off. I replaced the battery in the key, I think the cars computer might have been affected because the car sat with a dead battery for several months before I replaced it.

I was checking electrical connections to any sensors that might have come unplugged and noticed the intake ducting had come loose between the filter box and the motor. put that back on and I'm going to check it soon.

coil pak, mas air sensor??

What you describe sounds like a pretty good vacuum leak. Is this on a turbo car?

That would make sense. Regardless of air flow measurement, the initial squirt of fuel may get it running. Then when it starts to question how much fuel it should meter, when it's running, the lack of accurate air flow measurement kills it.

I've also seen similar issues with a fuel pump relay. The relay runs long enough to build prestart fuel pressure but then cuts out once the pump wants to go full on.

Mass airflow sensor
 

Hello buddy I had the exact same problem and I only changed the airflow meter right back to normal and I've been driving with the second hand one for almost a year now.