really idle wise you don't wana see any diff in pressure maybe car under a high load about 2 to 3 psi is acceptable. Temp sensor wise they do have a fault with the 1 st temp sensor but the once I have done in past register a fault code I would be going for vapouriser which you can test the resistance of btw. Just think of it as a glow plug it has a 1.6 ohm reading max. Also another test for blocked vapouriser is to measure across the delta of the dpf it should go higher than 150