Troubleshooting a loss of power issue

[arakele]

I bought a 2003 Pathfinder w/ 156k Thursday. On Saturday I was driving around with the kids and after a few hours my throttle response felt limited, almost like it became governed somehow. I could floor it and just barely accelerate. I made it home and noticed a slight burning smell that reminded of me of an old jeep I had when the catalytic converter went out. I checked the fault codes and only P0011 and P0021 came up. I know those codes are for cam sensors, I would not think they are related. I would have thought I would have received some sort of a fault code for the catalyst. After it cooled down I drove it again and it acted normal, no issues. I also noticed the mpg so far seems to be much worse than I would have assumed, which is also symptomatic of a bad cat.

 

Anyone else ever have similar issues?

 

Thanks!

[Blindaviator]

I was just watching some videos on Youtube for stopped up catalytic converters and yours sounds like it. Pick up an infrared temp gauge and you can determine quickly if it is the cat... Do a search on Youtube for plugged or stopped up catalytic converter.

Something like this: https://www.amazon.com/Etekcity-Lasergrip-1080-Non-contact-Thermometer/dp/B00DMI632G/ref=pd_lpo_469_bs_lp_t_2?_encoding=UTF8&psc=1&refRID=S529SVCJ97XRAHEE56MT

 

Basically you use the IR temp gauge to determine the temp of the exhaust before and after cat... The temp after the cat should be around 100 degrees higher than the front... If they are about the same or the front is higher it is likely the cat...

[Blindaviator]

I just found online another person having similar issues... This was the answer they got for the problem

 

 

P0011 and P0021 are mostly for Intake Valve Timing Control Performance.

Since the Intake valve timing control solenoid valve uses oil flow to control timing, dirty oil can cause the valve to stuck open or close. Before replacing the valve, change engine oil and filter and reset engine code.

Reset the light after. if you still have the same problem, remove the Intake valve timing control solenoid valve and clean it with brake cleaner.

 

So also check the oil level and change it. I just picked up a 2001 about a week ago and it has the VVT left bank code. I am going to try cleaning it before replacing as they are about $130 at Vatozone.

[Slartibartfast]

The governor effect you're talking about makes me think it may have been in limp home mode--something spooked the ECU and it limited power to prevent damage. I would expect it to run richer than normal in this condition, which would likely make the catalyst heat up. A failed catalyst would not have gone back to normal and you'd have secondary O2 sensor codes, so I doubt the catalyst is the problem. I don't know if the intake valve timing issue would put the ECU in limp mode, or if a stuck intake valve control whatsit would limit power on its own.

 

Not everything that goes wrong will code. My dad's '03 developed some problem with the swirl valve solenoid control thingus that made the truck buck violently if you tried to get on the gas, and it never threw a code. I would expect the computer to code for something that put it into limp mode, but I'm not too familiar with the R50 ECU so I'm mostly guessing here.

[arakele]

Yes thinking about it now, there were no o2 sensor codes thrown, so it's not likely the cat. I am changing the oil/filter and the transmission fluid/filter this weekend and will keep an eye on it. It hasn't happened since. It happened about 2-3 hours into driving around in 70 degree weather.

[Lazo32]

Check your motor oil if you ever feel down on power like that. The VVT head requires oil to function properly. Fill it up if low and check how she drives.

[Exorpmtech]

Id suspect a jumped timing belt with those codes and symtoms. Highly unliky both both banks are throwing codes unless it jumped time. What's odd is that you said it seems to be running better. I have seen the crank gear waller out and rotate a few degrees on the keyway of the crank shaft.