# 05 Pathfinder P0300 and NOT driveable



## 05PathfinderDriver (Dec 27, 2016)

I'll try to keep this short...

About 2 months ago I started having the issue where the truck would cut off while driving. I replaced the entire IPDM and that didn't fix it (I don't regret it since I had the old white one and from what I understand mine would have went at some point, replaced with new black IPDM). After the IPDM it threw the P0335 code, so I replaced the Crank Position Sensor... This completely fixed my issue with the truck cutting off while driving. Unfortunately I spent around $2k over the last 2 months replacing brakes, rotors, tires, and then fixing the stalling issues... so I was glad that the truck was fixed, but I was pretty much broke. 

A few days later I did start to notice a loss of power on interstate and it felt like I really had to give it a lot more gas to accelerate. Around this same time I notice my CEL would start to flash on and off and then it would go back to solid (I had a remaining code for steering angle sensor I hadn't been able to clear, but nothing other than that that I know of). I have also had terrible gas milage (like 14 MPG or so). 

Christmas morning I was driving to visit family and the truck had a MAJOR loss of power. I was able to pull over to a side street and cut the truck off and back on, but the problem was still there. The idle was extremely rough and if I try to drive the truck it feels like its hard to build speed and it won't go over 2500 RPMs (I can't even get it over 2500 RPMs in park). I was only about 3 miles from home and since no parts stores were open I decided to try to limp home, I made it about a mile from home. 

Monday I got a code reader and went back to the truck. It pulled codes P0011 (passenger side VVT solenoid) and P0300 (multiple misfire). I pulled the VVT solenoids off and cleaned them with brake cleaner and reinstalled them, this fixed the P0011 code, but I still have the P0300 code. 

Today I went back and put new spark plugs in, no change. I swapped the old IPDM in, no change (put the new one back after). At idle it still idles very rough and the whole truck shakes. When I try to rev it I can hold my foot on the gas and it won't go higher than 2k RPMs. When I put it in drive it acts like it's going to stall out immediately and since I can't rev the engine much I don't want to try to drive it and get stuck in a worse spot. 

I can't afford to take it to the dealership or a mechanic and I don't mind doing the work myself, but I'm just not sure what to try next and I really don't have the money to just start buying parts. Can anyone give me an idea on what I should try next and maybe a list to go down? 

BTW, I don't think I'm stuck in limp mode... Even after I reset the ECU (battery or clearing codes through scanner) I can startup without any CEL and still can't rev over 2k RPMs. 

I suspected MAF based on the symptoms, but from what I understand this should throw a specific code right?
I suspected it could be a clogged cat, but a clogged cat wouldn't leave me on the side of the road and unable to rev over 2k RPMs right?
I'm leaning towards fuel delivery problem... When I had the stalling issue a few weeks ago I did occasionally experience some bucking and hesitation when going 75 MPH on interstate, it felt like it wasn't getting enough fuel. I'm at 225k on the truck, so fuel pump could be going out. I'm assuming I should rent a fuel pressure gauge from a parts store and check this out?

I have searched a lot the last few days, but I can't seem to find any cases where people have P0300 and the truck is NOT driveable, all cases I can find their vehicle seems to lose power and come back or just acts sluggish. Thanks in advance for any help.


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## smj999smj (Jan 1, 2006)

It would be helpful to be able to look at the datastream info with a scan tool, but, unfortunately most don't have that option. Checking the fuel pressure is a good idea to rule that out as a possibility. Pressure spec is 50 psi. You'll need a fuel pressure gauge that can connect to the quick disconnect fittings where the fuel line connects to the front of the left bank fuel rail, at the front of the engine. You will also need the correct tool to disconnect the fuel line from the rail. Cam position sensor and crank position sensor failures are fairly common on these engines and don't always trigger codes. They can also cause driveability issues that can trigger other codes. Another area than can cause some driveability issues is the battery cable connections. Sometimes it's difficult to get the clamps tight, which results in poor connections, so make sure you can't turn them by hand on the battery posts. By your description, it doesn't sound like a clogged catalytic converter issue.


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## 05PathfinderDriver (Dec 27, 2016)

smj999smj said:


> It would be helpful to be able to look at the datastream info with a scan tool, but, unfortunately most don't have that option. Checking the fuel pressure is a good idea to rule that out as a possibility. Pressure spec is 50 psi. You'll need a fuel pressure gauge that can connect to the quick disconnect fittings where the fuel line connects to the front of the left bank fuel rail, at the front of the engine. You will also need the correct tool to disconnect the fuel line from the rail. Cam position sensor and crank position sensor failures are fairly common on these engines and don't always trigger codes. They can also cause driveability issues that can trigger other codes. Another area than can cause some driveability issues is the battery cable connections. Sometimes it's difficult to get the clamps tight, which results in poor connections, so make sure you can't turn them by hand on the battery posts. By your description, it doesn't sound like a clogged catalytic converter issue.


Thanks. I did shy away from checking the fuel system since it's been hard to get to a parts store the last few days. I may try that tomorrow while I can get a ride, but need to try to research it more tonight. 

Here is what I've done since the last post:
- Truck is towed home and easier to work on
- Did a compression check and all 6 cylinders are making good compression (this should rule out timing too right?) 
- Verified TPS sensor should be working (butterfly valve opened when holding pedal down)
- Pulled the coil packs and tested them with a multi-meter, those checked out fine. 
- Pulled both cam position sensors and both tested fine. The passenger side one looks like crap but still tests fine. 
- Removed the passenger front o2 sensor and started it, since this is before the cat it should let it breath if I have a clogged cat, but I didn't do this on the drivers side. I'm not sure this is worth bothering with on the drivers side since creating an airway on the passenger side didn't seem to help. 
- I pulled the MAF sensor plug off while the truck was running and the idle changed, but it didn't cut off. I was also able to start it without the MAF plugged in. From what I read this should prove the MAF is OK. We tried testing the plug but there isn't room to get anything (even a piece of thin wire) in to probe and didn't want to cut the wires. 
- Checked out battery cables and it's got a solid connection on both sides, battery is less than 6 months old BTW. 

What else to check or I suspect:
- Fuel system (could be injector or fuel pump, will use quoted advice and test the fuel system soon, hopefully tomorrow)
- Intake air leak (I sprayed some brake cleaner around the intake manifold a few days ago and didn't hear any idle change, but I'll try this again).


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## smj999smj (Jan 1, 2006)

Honestly, fuel injector malfunctions are practically unheard of on these engines. I would be more concerned about the fuel pump pressure. Cam and crank position sensor component tests aren't always reliable because often they fail when they get hot, but, they will test good when they are cold.


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## 05PathfinderDriver (Dec 27, 2016)

I ended up figuring out the issue about 2 weeks ago and have been fixing the mess 

I replaced both cam sensors and the PCV valve while I was back there, no change. That was about 3 weeks ago. There wasn't much left to check IMO, I felt either clogged cat, or bad fuel pump. I still didn't get around to testing the fuel pump due to the special tools... I had already removed the passenger side o2 sensor to test the passenger side cat and didn't see a change, so I decided to finally check the drivers side. Once I removed the drivers side o2 sensor the truck fired up and revved right up to 5k rpms! Now I knew my problem was a clogged cat. 

I got 2 new cats in the mail. When I took the passenger side off it looked fine. When I took the drivers side off to my amazement it was empty... like nothing inside but a thin metal ring that filled the largest diameter of the inside  So my cat apparently disintegrated and went further back into the exhaust and clogged the rear cat :| I ended up having to chop my pipe before the rear cat and angled it so that it dumps to the ground. It sounds nice up to 2k rpms, but past that is just awful :laugh: 

I have a Gibson Cat-Back and Doug Thorley mid pipes ordered, can't wait to hear it and have it drive normal again. After the cats, mid pipes, cat-back, cam sensors, and PCV valve I only spent about $1200. 

I'll update again and post how the truck runs and sounds after I get everything delivered and installed.


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## Louis808 (May 20, 2018)

Hey 05Path. I can not believe I have the exact identical symptoms you had with your Pathfinder. Like you, I searched high and low and could not find anyone with similar symptoms as I do with my 08 Pathfinder. I actually took my pathy into the dealer because I had no idea what the hell was the problem. I kept getting P0300 code. Since I have 112,000 miles on her, I replaced the spark plugs and all 6 coils with Hitachi brand. I cleaned the MAF—no change. Finally went to the dealer—$95.00 later guess what he said.
“All 4 of your cats need replacing. What kind of gas do you use? Do you use additives? Etc”
After replacing my spark plugs and coils it seemed my pathy was driving well and smooth etc. Then I went on the freeway to test it for 60+ mph. Immediately on the on-ramp I gave it a little gas and “bam” it sputtered, kicked, immediately lost power, Max 2K rpm, barely was crawling on the interstate. Put flashers on and pulled to the side of the road. Rough idle like it’s gonna die, shaking, etc. after opening the hood and checking to see if any coil wires or electrical connections seemed disconnected, I was able to downshift my gear to 2nd & 3rd with a max of 25 mph limping home which was only about 2 miles away. 
The changing of the plugs and coils did not fix the issue. I still have P0300 even with the new plugs and couils. I was getting horrible gas mileage prior to all this. So makes me think they killed my cats, as the dealer said.
So it appears the dealer was correct. Looks like my catalytic converters caused too much rich fuel to my cats, shown by my poor gas mileage, due to failing plugs and coils. 
I feel your pain and frustration! ??. I’m pretty handy so I will replace the cats and my O2 sensors myself etc. I’m sure as heck not buying the dealers cats. So I was curious what brand of cats did you buy and did you delete the secondary cats all together? 
I read you were going to put on B pipes. Are those in the place of the primary cats? 
I live in Hawaii, thank God we don’t gave SMOG checks. So not having cats is no issue. I just don’t want my Pathy to sound loud like a racer. It’s kinda a family suv.
Anything you can help me with in my questions I would deeply appreciate it. ?? Aloha


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## Louis808 (May 20, 2018)

Btw—-whatever advice SMJ has ever given me in relation to shocks, struts, coils, etc etc etc—-she’s been SPOT ON !!! Just thought I’d put that out there. I was one of the lucky ones with the trans fluid in the radiator and antifreeze in the trans nightmare. I was “LUCKY” to catch it early when it occurred, and her advice I followed to a “T”. Guess what—-no damage!!!! She knows her SH#¥. ???Mahalo again.


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