Hi,

Just bought a 2006 pathfinder 2WD a couple of months back. Transmission broke so got it rebult. Now when i drive, i see the "Service Engine Soon" light on. Got the code from Autozone, it read
P0850 - park / neutral switch input circuit
P0430 - catalyst system efficiency
C1163 steering angle sensor circuit

Not sure why this popped up after the tranny rebuild.
I tried unhooking the negative of the battery and plugged back in after about 30 min as suggested by one of my friend to get rid of the service engine soon light. It worked and everything was smooth and drive was better for about 10 miles before the service engine soon light popped up again.

Just wondering what could be the problem. Is it an expensive fix and can we do it by ourself. I have never done any kind of mechanic work.

Mileage is 154 K

Feels like an mistake buying a pathy. Not sure what else will go wrong.

Thanks,
KB

The steering angle sensor often occurs when the battery has been disconnected for some time. Most of the time, you can steer the wheels straight ahead, disconnect the battery for a few minutes and then reconnect it. Erase the stored code. Start the vehicle and drive forward and hopefully that will be it. If it resets, it could be that there is an alignment issue and/or the steering wheel position sensor needs to be relearned.
The park-neutral position switch is on the valve body, inside the trans. I would return the vehicle to the shop where the trans was rebuilt to address that.
If the catalyst code resets after being erased, it may be due to an exhaust leak from when the exhaust was removed to R&R the trans, or could be due to a bad upstream catalytic converter on bank 2, which is the driver's side.

The first thing I would do is rescan for codes and see if all the codes reset or just one or two of them.

which of these three has maximum impact on the engine performance and life. i have been driving with these for over 1000 miles but just wondering about expense. PNP switch, i will take back to the guy who fixed it but worried about other two.

Thanks again for your inputs.
KB

The steering angle sensor and PNP switch have nothing to do with the engine. The steering angle sensor would affect the stability control system of the vehicle.
The catalyst efficiency code refers to the ability of the upstream catalytic converter to break down the exhaust gases. If it is simply inefficient, it won't affect the engine performance and life. If the converter substrate is breaking apart or restrictive, than it will affect it.

Thanks for the info.
I just replace blower motor resistor for the AC myself which cost me $65 for which firestone quoted $200. so just wondering if PNP switch easy to fix ? I couldnt find any youtube videos.
Just a general question of how is the reliability of 06 pathfinder.
Mine has 154 k on it. What major expenses can you expect at this point for the next 50k miles ?

KB

To my knowledge, the PNP switch is not available separately; one has to get the TCM/Valve body assembly replaced and I believe the new assembly has to be initialized to the vehicle using a capable scan tool or CONSULT III.
I have 170,000 miles on my 06 LE, which I purchased with 84,000 miles on it. At that point, the previous owner had already had the fuel pump module w/ sender replaced and the upper timing chains replaced. He also had replaced the left bank, upstream catalytic converter and oxygen sensor. He also had the EGI relay replaced under recall. Otherwise, it was pretty much just general service.
Since I got it, I had to replace the right bank, upstream catalytic converter; I also replaced the front oxygen sensor, as well, while I was in there. The bolt for the primary chain tensioner, which I suspect was over-tightened when the chains were replaced, so, I tore that apart and replaced all of the chains, tensioner faces, primary tensioner and a couple of guides. I replaced the power steering suction hose because of leaking and replaced the radiator as preventative maintenance to avoid the cooler leak issue. Oh, I also had a leaking front strut when I first purchased it and the "belt squeak" which was cured by the updated belt and tensioner; both of these were taken care of by the selling dealer. Later, I replaced the other front strut just because the other had been replaced. Also, has a front propeller shaft U-joint go bad, so I replaced all of the U-joints. I replaced all of the TPMS sensors due to bad or weak batteries. Other than those items, she's been pretty solid. Everything else has just been scheduled maintenance or upgrades that I chose to do.

Thats scary considering the cost it might incur to replace the TCM/valve body assembly. Is this part outside the tranny or inside. i am sure it is not an easy fix for a common man to fix watchi any videos if available. Not sure what was fixed by the first owner on mine as i purchased when it had 152 K on it.

Does it make any difference if i use 87 grade gas instead of 93 grade with respect to the engine/tranny life. I have been using 93 grade considering the high mileage it has. just wondering is it worth using 93 grade as this is a gas guzzler.

Thanks,
KB

The transmission oil pan has to be removed to access the TCM/valve body. 87 Octane gas will work just find.

Thanks for all the information.