97 r50. Stalls and stutters when warmed

[PathCam710]

Hey nicoclub. I'm 19 and like to maintenence my own cars. Right now my 1997 Pathfinder 4x4 is having in order (small evap leak, vent control valve, h02s2 bank 1, vent control valve, crankshaft position sensor) I have put in 2 downstream 02 sensors and replaced CPS, when my car is cold it idles fine and drives fine (like many r50 problems similar to mine) but as soon as it reached operating temperature my idle will flutter, sometimes dropping below 500rpm, when I drive usually anything over 3000 rpm it will start to almost misfire, the rpm will surge down then back to 3000 and is associated with major power loss. I have no auto schooling experience I'm a strictly DIY guy using FSM and Google but I am at a loss and really frustrated.

[atraudes]

Welcome to Nico!

Is the check engine light on? What codes is it throwing?

[PathCam710]

P0440 Evap Small Leak (generic stored)
P0136 Ho2s2 Bank 1 (generic stored)
P0446 Vent Control Valve (generic stored)

P0446 Vent Control Valve (generic pending)
P1336 Crankshaft Position Sensor (Nissan pending)

[atraudes]

The P0440 and P0446 codes are both EVAP issues and most certainly not causing your major running issues. There's a couple of good threads on this forum on them, but this one's a good starting point. I wouldn't leave this be for too long, but you can deal with it at your leisure.

P0136 is a little odd since you already replaced the downstream O2 sensors. Did you reset the codes after you did? If it came back I wonder if the sensor you replaced it with is bad or if there's a problem with the wiring harness. For reference, P0136 indicates a problem with the passenger side downstream oxygen sensor.

I think P1336 is the big red flag. All of the threads I found on it described your symptoms to a T and pointed at the distributor actually being the problem. If you end up replacing the distributor, make sure you mark the precise location of it and its rotor before removing so you can reinstall the new one in exactly the same orientation. Installing it in the wrong position will mean it won't start, backfires, etc.

Sauces:
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post6432989.html
post6424681.html

Let us know how it goes and if you run into any roadblocks!