1999 S80 T6 Throttle Response Halts

[tiggs]

My 1999 S80 T6 with 138,000 miles recently developed a throttle response problem. It seems to halt at 2/3rds throttle. If I step on the gas it stalls between 2000 and 2500 rpm for several seconds then will go to 3000 to 3500 rpm for another several seconds then it may go to 5000 rpm. Check engine light came on (after 300 miles) and "service emission system required" message. Misfires on cylinder 1 and cylinder 2. Replaced the ignition coils and then cleared fault codes. Still throttle response problems exists AND no fault codes present.

Volvo replaced throttle body 2,000 miles ago under a "goodwill gesture" after a software update (recall) caused significant operational and performance issues. This car ran beautifully and with no hesitation before I had the "no charge" recall done on the throttle body.

This is a very frustrating situation. Your help is greatly appreciated.