Thread: knock sensor problem...again!

Sooo yesterday I took my car to a shop and got the sensor and harness changed (both from napa since OEM Nissan was around 170 and im tight on cash) the Guy said he adjusted my timing too..drove it for a bit..Boom engine light again ..I scanned it with my obd2 scanner and the po400 and the dam po325 pop up again..so I cleared it and been driving around for a bit..scanned it again and now only the po400 shows up...any ideas?

Check the timing... what did they put it to?