Nissan Repair: 2000 nissan quest rough idle, bosch platinum, vacuum lines

Question
A few months ago I cleaned the throttlebody, MAS, and poured a product called seafoam into one of the vacuum lines. I've used seafoam before in this manner with no problems. About a week later the vehicle developed a rough idle. It misfires a couple times every few seconds. The codes show a cylinder one misfire and knock sensor. I changed the plugs,wires cap and rotor with no change. I'm thinking either too much gunk got into the injectors or I damaged the MAS when I removed it. It sounds crazy but the problem seems worse after filling up the tank. Any thoughts? Thanks.

Answer
John,

Nothing you did here.  But, the knock sensor needs to be replaced.  Just the phase of the moon here.  Next, check the plug on number one to see if it is cracked since it is the only one showing a misfire.  If it were random misfire I would suggest looking at the distributor.  But, since it only shows one I would replace that plug.  I have cracked pulgs on installation and have had defective plugs like Bosch platinum.  So, do not use Bosch, I say this since I have had trouble with different cars with the Bosch plugs.  I like Nippondenso or NGK...