Try to get a scan up, mainly where the fuel trims are.
With an xp cam, you are going to have misses at idle, that is partly why the lope is, this is also why they disable the engine misfire trouble code when installing higher lift cams.
What type of wideband is it? Some of them need to be calibrated in open air before install. It's normal for the wideband to take about a minute or so to warm up and read the correct reading. Usually you will see it go from 14 to air in a minute or so if you hook it up and leave the sensor in open air.
