Jeep jerks when i take foot off gas

What is your question?

But I take the foot off the gas and decelerate the car bucks and jerks it has been to the mechanics several times the map sensor was just replaced in the car drove fine now it's bucking again after a couple weeks and the check engine light came back on it didn't come on when it started bucking but today the check engine light came back on the mechanic said he can't fix something that doesn't show a code for on the computer

What makes this problem better or worse?

When I take foot off gas it jerks

How long has your 2000 Jeep Grand Cherokee had this problem?

Off and on for about 4 months