My girlfriend just bought her new used 2000 Xterra 3.3 4wd 5 speed with 120000 miles! Signed the papers and before she got home the check engine light was on and when sitting at idle starts to flash! Original codes were p0300 random multiple misfire and p0325 knock sensor. First I ran some seafoam through the system, took it on a beat ride, then installed factory plugs replacing the 5 bosch platinum 2's and cylinder 6's original plug with no electrode left! No change at that point. After doing more research and talking to the Nissan dealer I installed a new factory distributor ordered by vin. Still no change. Installed factory wires with no change. Decided to tackle the knock sensor in hopes it was retarding the timing enough to cause the misfire. After new knock sensor, upper and lower intake gaskets, and a couple new coolant lines I took care of the knock sensor code!!!! Random misfire still occurring at idle, comes and goes at times. Decided to try the rest of the can of seafoam with hopes... denied! Any suggestions?