Nissan Repair: 2001 nissan pathfinder/Hard Starting and Loud Noise, nissan pathfinder, vacuum hose

Question
I have a 2001 Nissan Pathfinder that has now just started to give me fits. It is hard to start and wants to die and runs real ruff at idle. it also makes a loud knocking noise within the engine. When putting any load on it, it accelerates very slowly and will chug along a little distance and dies.
OBD codes: P1320
         P0420
         P0158
         P0420P
 Thanks You for all your help.

Answer
Hi Robert -

Looks like it is the swirl valve solenoid (code 1320). Replace that and you should be good to go.

Check for vacuum hose leaks to the unit first. The valve is located front of engine top, on a rack with another solenoid.

Hope this helps -
aloha
calvin