Hi, I have a 2001 volvo s40 turbo automatic with the codes below. I am experiencing stumbling during low idles eg. coming to a stop or sitting and lacking power. I have found one post on this issue but no answer of where to look for the problem. Any help regarding where to start looking for the problem would be much appreciated. By the way, all of this started a couple days after I blew the upper radiator hose and the cars temperature was up in the red.

p0172 system to rich bank 1
p0139 O2 sensor CKT slow response bank 1 sensor 2
p0301 cylinder 1 misfire detected
p0302 cylinder 2 misfire detected
p0303 cylinder 3 misfire detected
p0304 cylinder 4 misfire detected