Trouble Codes PO333, PO328, PO422

kippwimmer · Post by **kippwimmer** » 20 Nov 2010, 09:16

Recently purchased an '01 XC70 that now has an illuminated Check Engine light. Pulled three codes: PO333 Knock Sensor 2 circuit high input (bank 2),PO328 Knock Sensor 1 circuit high input bank 1 or 1 sensor, and PO422 Main catalyst below threshold. I cleared the codes and the light was out for a week then came back on. Has anyone had experience with this string of faults-any easy solutions? If the knock sensor(s) are faulty are they difficult to access/replace? Am I to assume the Main catalyst fault is the catalytic converter? Appreciate any help or insight !

kippwimmer · Post by **kippwimmer** » 06 Dec 2010, 06:43

seems I stumped the forum, with no replies, or perhaps no one has run into this problem?? In checking the location of the knock sensors for replacing, I moved around the connectors a bit. Once again, I cleared the codes and this time the codes have not reappeared over a two week period. Perhaps the trouble codes were a result of a poor connection. Time will tell.