PO734 Gear 4 ratio incorrect
 

so im driving down the road in my 2001 s80 t6 and my car goes into limp mode as if it's in neutral. so I stop the car, turn it off, wait a minute then start her back up and she drives normally for about 1 or 2 miles then she goes right back into limp mode until I repeat the process. I was hitting the throttle pretty hard before it happened but It was driving fine up to this point even when I would run it hard. engine is throwing a PO734 code please any help would be greatly appreciated

yeah that is an internal fault in the transmission. you can go to the dealer and see if the new service campaign for the tcm upgrade is available for your car. you can try doing that but its more than likely going to need a transmission.