Urgent help! CEL on and cannot find any answers!

Ok, here is what I believe to be the culprit and reason why the codes popped in the first place. The exhaust leak has been fixed with a little retightening down of bolts on the midpipe.

But, to that pesky p0352. I took my car to the mechanic and had him change the plugs (he guarantees his labor work for up to one year so if the plugs decides to shoot out he will fix it!!!) but anyways, he discovered a small amount of rust buildup in the cylinder #3 COP boot, as well as some dry rot and cracking of the boot. He told me and replaced it, problem fixed, that was Monday morning and I have put about 200 miles on the car (easy driving and hard driving) and not a single issue yet!