My 99 S80 T6, is pissin' me off. The check engine light is on and around 4000 rpm the engine seems to loose power and falls back to 3500. This naughty behavior repeats 3 or 4 time then finaly breaks through. If I give it more gas it will take off, leaving a puff of black smoke. When I do so it gives me a emissions servise message. The smoke is black, not blue or white, and there's no sweet smell, just an old truck smell. Help... thanks jon

 

I went and got all my codes pulled, I'm begining to belive that this maybe the end of my S80.
My codes are:
P0136 (O^2 sensor malfuction bank 1 sensor 2)
P0171B (system too lean)... this one made me feel really dumb (see title)
p0234 (Engine over boost condition)
p0236 (turbocharger bo?ost sensor A circuit tange/performance)
p0237 (turbocharger boost sensor a circuit low)
p0300b (random/mulitple misfire detected)
p1171 (electronic trottle system open)
p1174 (fuel trim adapter inactive bank1 malfunction)
p1132 (I DON'T KNOW WHAT THIS ONE IS)
p1132 (O2 sensor beated control circuit bank 1 sensor 1)

I had the fuel pump replace 2yrs. ago and last may had the sparkplugs and coils replaced. Over the weeked the car went into limp mode, after parking it in a parking lot for a couple of hours the condition went away. This morning when I started it, it went straight into limp mode, again a couple of hours later i was when i tried it again. its had exited limp mode. I ETM recall was taken care of back in 07, before I owned it. what can i do to fix it?