What is code 325

My book shows that as "Knock Sensor 1 Circuit Malfunction
(Bank 1 or Single Sensor)

I would guess either a bad connection or less likely, the new sensor is defective.

P0138 O2 Sensor Circuit High Voltage (Bank 1 Sensor 2)
P0139 O2 Sensor Circuit Slow Response (Bank 1 Sensor 2)
P0325 Knock Sensor 1 Circuit (Bank 1 or Single Sensor) -Circuit Malfunction
think you just need a new o2 sensor

answered this one

Get the codes read. you will get a better idea of where to start testing to repair this one. Most auto parts stores will do this for little or nothing. Please get back to me and we can trouble shoot this together.

Determine what the code descriptions of errors are. Then check and replace as needed.
Airbag light indicates problem with airbag system. You must visit the dealer to have analyzed and diagnoses given. Do not attemp to fix yourself. The airbag system, can cause severe injury or death.

P0325 NISSAN - Knock Sensor Circuit Malfunction
Possible causes- Faulty knock sensor
- Knock sensor circuit short to ground
- Knock sensor circuit short to power
- Knock sensor circuit open
- Faulty Engine Control Module (ECM)

Read more: http://engine-codes.com/p0325_nissan.html#ixzz29K4BM3th

My Nissan micro 2004 model just stopped in the middle of the road one day then the engine management light came on, anyway took it to my local garage TWK Thomas who said it was a cam shaft sensor problem. OK so sensor was put on, engine management light went off for two days only. So went back to the garage they said that another sensor should be fitted on the opposite side. And then the problem should be rectified, but i had given the £160 for this problem to be fixed the first time. I decided it was time to take it to another garage Nis Tec they put it on the computer and a code po340 came up would this mean another sensor or the cam chain has stretched please help. ...claire

the PO 325 code is for VSS vichicle speed sensor and PO500 is for a knock sensor,so you will need to see what the new code is to be able to help you, the engine power manegment is controled by both get it scanned by autozone or the mechanic that did the work and see if it's the same code, if it is you may have a short or an ecm going bad. let us know what codes you find.

744 is to do with your torque converter clutch circuit, intermittent malfunction. 325 is knock sensor malfunction. Has vehicle been shifting different, probably at highway speed? (cruising) Have you noticed engine "ping"/"rattle" on acceleration? These would be common occurences with these codes.