common cause is maf sensor.
may fix it if all else fails
turbo overboost
Trouble code P0234 means:Engine overboost condition
The 2001 Volvo S80 has 24 valves.
The 2001 Volvo S80 is a gas-powered vehicle.
The 2001 Volvo S80 has an inline 6 engine.
The 2001 Volvo S80 has a 4-speed automatic.
The 2001 Volvo S80 has double overhead cam (DOHC).
The height of the 2001 Volvo S80 is 4 ft. 9.2 in. (57.2 in.).
The 2001 Volvo S80 is 15 ft. 9.8 in. (189.8 in.) long.
The 2001 Volvo S80 has 56.9 in. of rear shoulder room.
The 2001 Volvo S80 has 37.6 in. of rear head room.
The 2001 Volvo S80 has 35.9 in. of rear leg room.