2002 Pathfinder 3.5 Multiple odb codes need help quick!!!

[ajgordo04]

This is my 1st first post, so Hi everyone. I browsed for a few hours earlier, it seems that there is a wealth of knowledge on here. I hope that you guys can help me out. Being that my issue does have many threads already, I didn't really want to start a new one, however after searching, I have only found people having 1 or 2 of the issues that I am. My hope is that by starting a new thread you guys will be able to see the whole picture and be able to advise me better.
So here is what is going on. Vehicle in question is a 2002 pathfinder with the 3.5. Automatic transmission, 2WD. Wife was driving normally on a nice day, temp around 50-65. She states that the car all of the sudden lost power, almost died. She was able to get the side of the road and get the vehicle in gear. At that time the motor was still running but really rough. She tried to put back into gear, car started vibrating really bad, killed the motor. Friend picked her up. I went to look at vehicle later that day. Got there stated it up, rough rough motor. The intake was making a grunting sound, popped real loud. Read codes, they were misfires and o2 sensors cant remember exactly. Also found out that they had been on for about 40,000 miles (bulb must be out or disconnected--im leaning towards the latter). We have only had the vehicle for about the last 6-10k miles. Doesn't really matter to the issue, but there ya go. Limped car to parking place about a mile down the road. Couldn't find anything obvious wrong. Had truck towed to a mechanic that I personally hadn't used, but my sister had. She said that her experience was good so i trusted her. Few days go by, get in contact with mechanic. He states that the issue is that the catalytic converters are clogged. Price was 1700, he said that he'd keep looking, price came down to 1400, then 1250. That diagnosis just didn't seem right to me, the symptoms didn't add up and guy seemed kind of shady. Also keep in mind that I personally never got the opportunity to speak with the mechanic, he was always out, on the phone on busy and would call back-- never called me. The shop and even the mechanic personally were happy to talk with my wife anytime she called. Anyway... told mechanic to just put it back together and that i would pay diag fee and pick up. The receptionist put me on hold for about 20 min then finally came back and said that he ( the mechanic) would call me later that day, he had to add everything up ( i had only authorized a diagnostic). Next day still no call. Wife calls up, they tell here that the vehicle is ready to pick up and that we weren't being charged anything because the repair was so expensive...
There's the background, heres is where i'm at.
Got vehicle home. Battery had died (could be important). Jumped vehicle, seemed to start ok, and idled, sort of, with some coaxing. Tried to rev, sputter sputter, engine dies. Like before, When revving the intake box makes a grunting sound. some times it pops real loud. Pretty sure that is due to the misfires. So I hooked battery charger back up (figured it needed it anyway) and read obd codes. I have two readers, one simple on from autozone, and one on my iphone. Its a cable that goes from obd2 to iphone, the software is gopoint. Pretty neat setup and actually surprisingly powerful. It will read, short and longterm fuel trim for both banks individually, o2 sensors, maf reading, etc.... lots of info available.
The codes I got the 1st time were:
p0300 - Random/Multiple cylinder misfire / Misfire on multiple cylinders
p1140 - Bank 2 sensor internal resistor (o2) / Mass or Volume air flow circuit / intake valve timing control
maf reading was at 0 regardless of throttle position. I tested old maf with multi-meter, found that the output voltage was not varying with rpm or throttle position. According to logic and everything i have read that part is bad, and root of issue. I spent the $284 and some change, got new part, installed, reset ecu by pulling battery. Reconnect battery and started. Truck started right up, and idled smoother. Still would not rev without sputtering and eventually dying. ( not dying when throttle drops like iac valve issue, dying randomly) It would almost try to run smooth then putter out. Tells me something may be up with the timing. I run obd scan again. These codes come up:
p1140 - Bank 2 sensor internal resistor (o2) / Mass or Volume air flow circuit / intake valve timing control
p1145 - same thing bank 1 + solenoid valve running losses
looked up those issues on here. and took some of the steps mentioned
pulled both cam timing sensors - they were covered in gunk ( if i get the damn thing running will be doing some sort of flush!!!)
Cleaned them up, reinstalled codes still there. ok reset ecu- battery, while that was disconnected i pulled both solenoids, left and right, They were also pretty dirty, cleaned them as well. ( interesting note, the bank 1 passenger side solenoid, did have some gunk but for the most part was very clean. Really it looked brand new, I have a feeling that it may have been a new replacement part). Both solenoids did seem to respond to voltage and voltage was being supplied by the harness. Reinstalled everything again after cleaning. Reconnected battery and attempted start up. Engine started up, idled pretty smooth (better then it have been) I was still getting the intake pop/grunt though.
Calling it a night, I put away tools and decided to run one more code scan and looks like i'm worse off now than before...
p1148 - Catalyst temp. sensor 2 circuit / Diagnostic module tank leakage / evap canister, purge valve, and vent control
p0102 - Mass or Volume air flow sensor / mass air flow sensor low output voltage
p0300 - Random/Multiple cylinder misfire / Misfire on multiple cylinders
p1140 - bank 2 sensor2 internal resistor / mass or volume air flow circuit / intake valve time control
p1145 - Mass or Volume air flow circuit / solenoid valve running losses / intake valve timing control / mas air flow sensor short
p1614 - call-up circ/tranm. controler / electronic throttle system module / mil request circuit voltage high
p1136 - long term fuel trim / o2 sensor heater circuit high / o2 sensor bank 1 sensor 1 heater / long term fuel trim

I am at a loss. Problems seems to stay the same no matter what, but the trouble codes this thing is throwing don't seem to be helping me diagnose, just making more questions. Any thoughts, ideas, solutions would be greatly appreciated.

[Chuck Tribolet]

I think you need an FSM. Some of those codes don't match your descriptions. If your software is telling you what they mean, it's often wrong for the codes 1000 and up which vendor, or even vehicle, specific.

And the cam advance stuff won't screw the truck up that bad. It will just cause a bit of loss of maximum power.

Chuck

[Towncivilian]

Based on the quick and seemingly random engine power loss and large amount of codes, I'd hazard a guess that one or more power valve screws backed out and were ingested by the engine, causing the rough running engine and catalytic converter damage. See this thread for some more details.

I'd also echo Chuck's suggestion of downloading the factory service manual. You can download it here; to save a copy of the FSM, right click -> Save As on every PDF, save them into a single folder, then use fwd.pdf to navigate.

Welcome to NICO, sorry you've found us as a result of such trying circumstances!

[Buzzman]

Based on the quick and seemingly random engine power loss and large amount of codes, I'd hazard a guess that one or more power valve screws backed out and were ingested by the engine, causing the rough running engine and catalytic converter damage.

First thing I thought of, even before I finished reading the whole initial post.
Also, an independent mechanic not familiar with the Pathfinder/QX4 or this engine, would never know about the power valve screw issues.
I don't think the news will be good.