2006 Pathy P0430 P0420 codes

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jrobers
Posts: 51
Joined: Tue Sep 09, 2014 1:14 pm
Location: Midlothian, VA

2006 Pathy P0430 P0420 codes

Postby jrobers » Thu Mar 22, 2018 8:22 am

I've recently developed these codes. The P0430 comes on often, but the P0420 doesn't come on near as much.

I developed the rough idle and it drives me nuts. I'm told a motor mount is wearing but not worn out yet and that could be the issue of the rough idle.

Around the same time My trucks started to run really rough in the winter. Sounds like piston slap and really rich exhaust smell until it warms up.

Could any of this be related to bad cats, or is something else the likely culprit like injectors or an exhaust leak?

I'm trying to weight repairing vs selling and I love my Pathfinder.


twinblown
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Location: Central Florida

Postby twinblown » Thu Mar 22, 2018 4:50 pm

motor mounts do not cause rough idle. Old or bad spark plugs, plug boots, bad ignition coils and vacuum leaks do. Continued driving with a miss will ruin your cats because raw fuel is being dumped. Good luck .

jrobers
Posts: 51
Joined: Tue Sep 09, 2014 1:14 pm
Location: Midlothian, VA

Postby jrobers » Fri Mar 23, 2018 5:33 am

Good info. my plugs are about 3 years old maybe 20k miles on them. How would you know if you need to replace the coils packs? I don't think it misfires or anything. I'm wondering of I have a crack in the manifold. I plan to check that out this weekend. I plan to drive this for another few years, maybe it's time to replace the coils and plugs just to be safe.

triplesnake
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Location: TX

Postby triplesnake » Tue Mar 27, 2018 1:52 pm

I haven't heard about it with the Pathfinder motors, but I know that the exhaust manifolds are prone to cracking on both the first gen Xterra and the Titan. On my Titan the 430 code was the symptom. So, you might look carefully for exhaust or vacuum leaks.

jrobers
Posts: 51
Joined: Tue Sep 09, 2014 1:14 pm
Location: Midlothian, VA

Postby jrobers » Fri Mar 30, 2018 6:10 am

I'm going to inspect the exhaust, but I'll need to read up on how to check for a vacuum leak.

The gray rider
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Re: 2006 Pathy P0430 P0420 codes

Postby The gray rider » Wed Oct 12, 2022 3:57 pm

I'm not sure where to post this since there are so many threads regarding "rough idle," but maybe my point will get around, if it hasn't already.

I'm the original owner of an '06 Pathfinder. In April of 2014, at 105,000 miles, I had the timing chain, guides replaced for noise.
Fast-forward to 2019, started to feel a rough idle. Wondered if it had something to do with worsened gas mileage. I lived with it.
In 2021, the check engine light throws the code for CAT converter. That code, we all know, is not very specific and can mean many problems. I had the bank-one CAT converter replaced.
The code returned. I replaced the bank-one-after-CAT O2 sensor.
The code returned. I replaced the before-CAT O2 sensor.
The code returned. I checked the exhaust for leaks and found one at the CAT-exhaust joint. I replaced the gasket there, but the leak persisted. I took it to a shop and it was found to have a pinhole in the exhaust near the gasket. Welded it.
The code returned. I replaced the MAF sensor and cleaned the throttle, which looked fine.
The code returned. Because the low idle sometimes causes the oil pressure gauge to dip, I changed the oil out for 10-30 in hopes of tightening things up.
The code has not returned!
But the idle is still rough. I love this rig but for this stupid rough idle. I searched the net for answers, aggressively at first, then half-heartedly. Then, I found this:
https://www.motor.com/wp-content/upload ... E_0116.pdf

I think this is my problem. I don't know that Nissan replaced the gasket material in the rear timing cover. Probably not, since it's not necessary to do so to replace the chains.
My dilemma is fixing this (or attempting it.) It's a 20-30 hour job for me or probably 3 to 4 grand. I have upgraded this 4x4 from grocery getter to off-roader. I still have more upgrades in mind. This problem makes thinking of buying an FJ more palatable.

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VStar650CL
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Re: 2006 Pathy P0430 P0420 codes

Postby VStar650CL » Wed Oct 12, 2022 4:23 pm

P0420/P0430 pretty much always mean a bad cat. They are very specific, the only other thing that causes them (infrequently) is an air leak upstream from a rear sensor. Unlike the front A/F sensors, leaks downstream from the rear O2's won't usually affect them because any "back-and-forth" from Miller-cycling is damped out inside the cat. So the bottom line is, those sensors were probably perfectly healthy. What you have is a dying cat. Yes, if it's partially plugged it can cause a rough idle and a host of other things from imbalance in the air being moved by each bank. Engines are air pumps, they need to breathe.

The gray rider
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Joined: Mon Mar 15, 2021 1:47 pm

Re: 2006 Pathy P0430 P0420 codes

Postby The gray rider » Thu Oct 13, 2022 6:23 pm

Thanks, vstar,
I stated that I had that CAT converter replaced. It was only after the oil mod that the code quit returning. If it is another CAT failing, I should be getting the code.
Many others say these codes are potential issues with:
Exhaust tube issues
Intake air leaks
Faulty oxygen sensor
Faulty fuel injector(s)
Leaking fuel injector(s)
Faulty spark plugs
Improper ignition timing
Faulty engine control module (ECM)
Dirty air filter...

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VStar650CL
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Re: 2006 Pathy P0430 P0420 codes

Postby VStar650CL » Thu Oct 13, 2022 6:28 pm

So you did. Sorry, my bad. If it's an aftermarket cat, you probably just have a weak one. Try a spacer on the rear O2.

TooMuchControl
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Joined: Tue Apr 28, 2020 4:41 pm

Re: 2006 Pathy P0430 P0420 codes

Postby TooMuchControl » Sat Oct 15, 2022 11:28 am

On thing to check for rough idle. The actual idle RPM.
It makes a huge difference on what 25-50 rpm does at the low end.
My truck would idle poorly and I couldn't understand how, since everything drove smoothly.

I have a Foxwell Diagnostic Tool and I was able to change it, and it resolved it.

It caught my attention once, when I took the truck to the dealership and the mechanic said he noted the idle RPM was low (he adjusted it). I went in and did a better check. Done.


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