Of 3 weeks duration, about 1 or 2 out of 10 starts from stopped or slowed position, or going around corner/up hill, get a 3-5 second hesitation at 1500-2000 RPMs (falls back to 1000 RPM) then recover to normal. Not an expert, mind you, but seems to act like not getting fuel for those few seconds...cannot tell if related to changing gears.

Seems to be without regard to full or empty gas tank, ambient temperature, hot or cold engine. Starts, idles, runs, changes gears perfectly at all other speeds/RPMs (at least so far). Has had routine maintenance.

Since had Check Engine light, went to both regular very experienced independent Volvo mechanic, and yesterday to Volvo dealer. Codes were Emission/Evap-related. There was a vacuum hose leak - replaced, and check engine stayed off 3 days, then came back, same codes. Upon test driving, of course, neither could replicate hesitation.

Both say codes likely unrelated to performance issue. Both say 'hope it throws a different code'. Started car this am and check engine on again -same codes. No codes to indicate anything else.

Have been through FAQs, threads, etc., and am not seeing similar issues to compare. Again, not expert, some seem possibly related, such as fuel pump, filter, regulator (?); spark plug wires, coil wires, overflow fuel drain (?)

Any ideas, help, advice most welcome...(sorry to go on...) Addled in Atlanta..