Hey guys pls read the story and give your input..

2001
4.4L
120,000KM

I took a trip down to Seattle this weekend.
on the way there, on the I-5 doing about 80km(getting on a on-ramp), The X stalled for a quck sec., yellow ! light, abs, trac control, and ENGINE FAILSAFE PROG appeared.
I shut off the car and restarted it was normal...until another 5 min and same thing happend when STOPPING.
the lgihts went off and i continued to drive, and I went to pass a car and when i floored it, my check engine light flashed and stayed on.

I got to the hotel, and took on and off the connections to the battery and it was all fine, until on the way back home same situation; I depressed the accel to the floor and check engine light was blinking and then shut off...

MONDAY- i took it to Brian Jessel BMW
I got a call saying my bill is at $880 for diag(said that cyl 1 and 2 were misfiring the DIS sheet said that check engine kicks in at 5100rpm), new plugs, and checked to see if its the injectors...BUT THEY STILL DONT KNOW THE CAUSE PROBLEM!
The service advisor told me this" I think its best to trade in your car, if you want us to keep going it could be $5000min" What kind of advice was that!?
So I took my car and paid the bill but you can still hear the car misfiring if i rev it up just a bit through the exhaust.
Any idea on what it is?
Anyone else have something similar?