stumbling on acceleration then catches multipal times has

this happened after it was serviced,said computer update was done at same time. also after service poor mileage lost about 5 mpg. and pep it had before.old school said they messed the timing if you can still do ??

Update from Jul 17, 2016: had outlander serviced at dealer, they said every thing checked out,but he reset computer back to factory preset which when they did update on software they may have not done.they also listened to my complaint about poor gas mileage.I brought all complaints from your site with me printed out, we all can't be wrong, that was wednesday, vehicle has been running like it was, mileage has increased like it was, I think this site really helped especially seeing same complaints all across the country. keep up good work 07/17/2016