Citron

Easy enough to test. Get a multi meter and test for voltage on both main lugs of the solenoid while someone turns the key. If you get battery voltage on both lugs while the key is in start, then the solenoid is fine. Should only take a minute or two to check. If you don't have a meter, then you can jumper from one main lug to the other. If it turns over then the solenoid is bad, if it doesn't turn over then starter motor is bad, provided you have battery voltage at the starter to begin with. Be careful doing it this way as you will get some arching and sparking.

That does seem like a lot of oil. If you are not leaking that much, then you must be burning it. When you start it cold, does blue smoke come out of the exhaust? Check the coolant and see if there is an oily film in it. Also, for the rough shifts, change the tranny fluid and tranny filter. This will require dropping the pan, and can get messy, but is pretty easy. The torque converter should have a drain plug. This will get another 4 to 6 quarts out. That is the best way to get the most fluid out of the tranny.

I have a similar problem on my Titan. I have found that if I try to start it shortly after shutting it off, it will not start. If I turn the key on for a few seconds to let the fuel pump run and build pressure, then it starts no problem. It is habit now to always turn the key to run for a few seconds before starting. Does this work on your pathy, or do you need to let it completely cool down before starting?

I had a similar problem with a 22re toyota pickup years ago. I took the starter out, took it apart and cleaned all of the carbon dust and crud out, and put it back in. Got another year out of the starter before needing to replace it.

Great advice. I don't have enough experience with pathfinders to know where cut-out relays are located. However, unless it is wired differently then I am thinking, the fact that he is getting power on the coil wire for the starter solenoid would mean that the relay on the firewall was functioning. If that relay had failed, then no power would be at the solenoid, correct? It is hard without a wiring diagram to look at.

I have a 92 and I can't remember it having the misfire, however it never sees pavement so I haven't had it past third in a long time. It is gutless at low rpm though. Just to rule it out, you could ohm the spark plug wires. I seem to remember that they are supposed to ohm between 6k-8k ohms. I have seen one time were a plug wire had voltage leakage due to bad insulation. I think you are on the right track with the injector.

When you say tune up, you are referring to plugs, wires, cap, rotor, fuel and air filter? Just trying to get an idea of all that was replaced. If you pull the plugs and one is black, you know that is the cylinder that is not firing. Sometimes misfires are there all the time but at higher rpm it is hard to tell because everything is happening so fast. I believe these trucks have a knock sensor so a hard misfire should throw a code.

If you are getting battery voltage on the big cable, and you have voltage on the small wire that lands on the small starter lug with the key in start, then you have everything you need for the starter to function. There should not be a fusible link in that wire heading to the starter. I would try to verify that all of the connections are tight on the starter, but at this point, it sounds like it is the starter coil that is bad. Removing the tire and removing the little flexible plastic piece in the wheel well may give access to the starter. Since you have voltage on the small lug at the starter, then it wouldn't be an auto start causing the problem. Those usually intercept the wire under the dash. Sorry I can't give you wire colors, I don't have a wiring diagram, and I can't walk out to my pathfinder and look because I am on vacation.

Easiest check is always the fuse. The owners manual will tell you what fuse/relay is associated with the start circuit. if all the fuses are good then start diagnoses on the system. Do you have a multimeter? Should be three lugs on the starter coil. Two big ones and a small one. The small one is from the ignition start circuit. use your meter to measure voltage on that lug while someone has the ignition in the start position. If no voltage there, then the problem is in the ignition start circuit. If there is voltage, then verify battery voltage on the large lug that runs up to the battery. If you have voltage there, then check voltage on the other large lug while someone turns the key to start. That will tell you if the coil is switching or not. There should be battery voltage on both large lugs with the key in start. I imagine it is not switching since you hear nothing. If it is not switching, you can verify the coil is bad by removing the wire from the small lug, and ohming from the small lug to the starter body. I am not sure what a good Nissan coil should read, but it should be fairly high. Sorry I can't be more specific, I am unfamiliar with these vehicles, I was trained on Fords. Let us know what you find. Hope this helps.

True, but that only tells you the condition of the whole o2 sensor circuit. If either check you described pointed to the o2 sensor circuit, you still need to verify if it is the sensor or something further down the line in the wiring and/or ecu. It would be very lame to change the sensor based on on of these checks, then have the same problem because a wire was loose in a connector further down.

If you change the sensor, make sure not to get any sort of thread treatment (anti-sieze) on the sensor itself as it will ruin it.

Supposed to say ohming from sensor body to exhaust pipe. Curse auto correct!

I think the problem may be simpler. If the cat really got red hot, you probably damaged the o2 sensor. This is used by the ecu to adjust the air/fuel ratio. A failed one will cause idling, running issues. You can use a multi meter to check it. On this vehicle it is probably a two wire sensor. You can ohm it to see if it is still good. The FSM should tell you the ohm spec. If it ohms out, check for voltage on the voltage reference wire. Check out put on the signal return wire. Do both by backprobbing the connector. It is case grounded, so verify a good ground by phoning from the sensor body to the exhaust pipe. Proper diagnoses of sensors before replacement will save lots of money and frustration. Hope this helps.