Owner's manual should list the recommended replacement.

 

Hi Tomat

it does, but go for $19 per plug...thinking of going with NGk 4469

 

OEM plugs are only $12.99 each.

 

Do yourself a favor and get the oem plug. You will save money in the long run.

 

I recommend NGK PLFR5A-11, or the stock number is 6240. Same plug. .043 gap. Put a SMALL dab anti seize on the threads. I hope you have by passed the trans cooler lines at the radiator? If not DO so at once I recommend. Questions ?? Check the PVC hose on the passenger side . It run to the back of the engine. I bet it is very hard. If it cracks it will allow air to enter and run lean. Dealer Item. But it needs changing. Maybe the PCV valve too ? It's very hard to get to. Questions ?? Jerry.

 

Hi Vegas

Thanks for the reply..."Amazon" said it doesn't fit my 2008 Frontier...but I used these in my 2006 Pathfinder with no problem?

I have done the radiator/tranny bypass on both vehicles. I changed the PCV on the Pathfinder and will do so on the Frontier this weekend.

 

The NGK 6240 Laser Platinums will work fine in 2007 and later VQ40DE engines; it was the stock plug on the 2005-2006 VQ40DE engines and then Nissan went to the Laser Iridiums in 2007. In the same sense, you can use the Laser Iridiums in the earlier, 05-06 engines. You will not notice any difference in performance. The Laser Platinums are a few dollars cheaper per plug. Both have 105,000 interval schedules, but the Laser Iridiums will actually last closer to 120000-130000 miles.
As far as putting a dab of anti-seize on the threads of the plugs, NGK actually recommends using nothing on the thread as it can have an affect the torquing of the plug during installation, which is 18 ft/lbs.

 

Did you have fun changing the hose and the PCV valve on the pathfinder? Maybe there was more room to work back there.? You found that hose to be very hard didn't you?

 

Vegas...do you know the part number for the hose from PCV to manifold?

 

I took an old 24mm or 3/4" wrench and cut it in half.....only could unscrew it 1/4 turn at the time....the hose wasn't fun getting off either...but I did change the plugs without taking the intake off.

 

amazing that you got the right front plug out ? Have you cleaned the Mass airflow sensor and the throttle body? CRC makes spray chemicals just for them. separate products. they work great !

 

I had heard & read to never physically gap iridium plugs due to potentially damaging the thin iridium layer. Just use them straight out of the box? True or not?

 

NGK and Denso plugs are gapped at the factory, so unless the plug is dropped, there is usually no need to adjust the gap on them. I do know they say you should never gap used platinum or iridium plugs; only adjust them as needed when they are new.

 

I just bought and put in some NGK LFR5AIX-11. My 08 Frontier V6 had the original plugs at 101K miles. Came pre-gapped at 0.043. I put some anti-seize on them and torqued them down to 15 ft lbs.

Pic of old ones...first three on driver side second pic is passenger side

 

What was the gap n the old ones when you removed them . Much wider than new?

 

anywhere from 0.41-0.44

 

The LFR5AIX-11 plugs are the Iridium IX plugs, which are Nissan's economy, iridium spark plug. They'll work fine, but should be replaced at 60,000 mile intervals instead of the 105,000 intervals for the Laser Iridiums and Laser Platinums.
As far as the anti-seize, Nissan found it can affect the torque specs as much as 20%. NGK plugs have a metal shell that are plated and should not be lubricated at initial installation. NGK released a tech support bulletin on the issue:

http://www.jagrepair.com/images/AutoRepairPhotos/NGK_TB-0630111antisieze.pdf

 

The NGK LFR5AIX11 is listed as NGK's premium product specified for Frontiers. I don't know where you see it as an economy product. And while they don't specify plug lifespan on their website, everything I've read is all Iridium plugs are good for 105,000 miles. These "premium" plugs, per NGK, are a quarter the price of the OEM,s largely I suspect only because they play on people's fears of not buying the original OEM product. So they jack them up costwise.

 

I’ve always been told not to use anti-seize on anything that needs to be torqued so you can get the proper torque value.

Clint

 

Thanks guys...these seemed to be gapped perfectly and I did not adjust any.

For antiseize, I took a small dab, smaller than a Q-tip, rolled it around my fingertips and then rubbed some on the threads. Saw some videos where folks had the threads coated way too think I would think. The old ones whined and screeched getting them out; afraid I was going to break one off.

 

You did perfect by adding the anti seize in just the right amount. Now your next project is cleaning the mass air flow sensor, and the throttle body. The air sensor is the part that's sitting up in the air tube from the air filter to the throttle body. It has 2 phillips screws, and wires connecting it. U need a special cleaner to use on it. CRC makes such a cleaner. Can't hurt the plastic parts. The air flow sensor regulates how much fuel to send to the computer. It gets gummy and things stick to it as the air from the filter flows past it. U will notice a big difference in the idle and running once you clean it. Then clean the throttle body. It's the plate that opens to allow air to pass to the engine. Brass colored most likely. CRC also makes a cleaner just for it too. Use a clean rag to clean the plate. Avoid spraying too much cleaner there. It runs straight into the cylinders. Wal mart has both . Questions ?? Jerry..

 

Thanks Jerry...it is on the list to do!

 

Adjusting Iridium plugs aren't a problem. I've done it on a few of my cars throughout the years with no ill-effects. Had to decrease the gap due to running more boost on my turbocharged cars, then had to eventually run one step colder than stock to keep up with the modifications. But I usually ever so slightly tap the ground electrode on a clean smooth concrete floor like your garage to decrease the gap. And if I decreased it too much, I use one of those round spark plug gap tools to pull the ground electrode back up ever so slightly also til I hit my gap I want.

 

I am also thinking about going with 4469 (LFR5AIX11) Laser Iridium IX. For one thing, the OEM plugs (93759, DILFR5A11) are outrageously priced at $14.57ea on eBay I suspect because people think that's what they have to use. The 4469 are $5.36 and a higher rated plug by NGK.

 

I got mine at Autozone; think I paid $8.99 per plug. But 5 miles away and they were instock for immediate pickup. Came pre gapped perfectly.

 

Yea well, my mechanic told me $44 each for the OEM which I'm sure reflects 125% markup.

 

Clint NKG recommends reducing torque by 30% if using anti seize compound

http://https://www.ngk.com/learning-center/article/522/plug-torque-settings

http://http://ricksfreeautorepairadvice.com/anti-seize-spark-plug-threads/

 

The torque number for plugs is not best way to install plugs.. The plug is turned down until the gasket is crushed. Best is too turn finger tight until the gasket is captured then tighten 3/4 more with a wrench. Perfect crush regardless of torque. Instructions on box.

Tt

 

Spark Plug Replacement - 4.0

My Nismo is well into middle life and certain components are failing or need maintenance. At 108k it was time for the sparkplugs.

I chose to use the NGK LR5AIX-11 4469,"Iridium IX." They were not pre-gapped correctly (0.043 in.) so I used my trusty tool to bend the "L" electrode to spec.

Changing the driver's side bank (#2-4-6) is a can of corn. Two of the passenger side plugs (#1 most distal to the driver & 3) are blocked by the intake plenum. All do-it-yourselfers must choose to take off the intake or to finesse with swivels and close quarters skills to get these two replaced. I chose the remove intake route for which there are many videos on the internet to help. I did not replace the intake gaskets. Those skilled in the trade say the intake route takes 2 hours. For me, it took most of the day as I moved cautiously. Fully 90% of my efforts were consumed with the freaking intake. I can see why the dealer would charge $400 for this PITA job.

No anti-sieze for me. Torquing in close quarters is difficult so I used 0.5-.75 wrench turns after bottoming to set the torque. Care should be taken in torqing the intake bolts - just enough to compress the intake gaskets (21 lb-ft). I suspect overtorqing will damage the plastic intake before the aluminum head.

The old plugs were worn and the 4.0 now has new pep with the new spark plugs and hopefully better mpg.

 

After doing a few sets without taking off the intake, it takes me about 40 minutes to do a set of spark plugs that way. The next time I do them, it'll be the first time since the XTP plenum spacer was installed, so I anticipating there will be a little more room to work with!

 

Another method



Do you think a third way to handle the passenger bank is to take off the tire and fender liner?

 

Big Problem! Engine codes: P0420 and P0430

A few days after replacing the sparkplugs, my ECU issued two check engine codes: P0420 and P0430. These relate to the performance of the right primary catalytic converter and the left. Hummmmm? How can changing the plugs affect both banks of converters?

The codes are issued if the performance of the cats is not up to snuff. This assessment is done by measuring oxygen levels before and after the cats. Logically, it makes sense that an O2 sensor can be bad. But I would need two to go bad in a short time period for two codes to be registered.

The new plugs probably ignite a more efficient combustion which can lower the O2 in the engine's exhaust. Does it take time for the engine to "learn" the new O2 profile.

Another common point is the MAF sensor. This was left open during the intake plenum removal. Could it have been contaminated?

Cats are costly so I will research this completely before spending the $$$$. The definitive test seems to be temperature rise between the input and output of the cats. Has anyone used this method and is it reliable?

 

I would clean the MAF sensor hotwire, make sure there are not air leaks (check the rubber ducts on the intake tube as they are known for splitting), erase the codes and self-learning memory and see if the catalyst codes return. It wouldn't hurt to confirm proper fuel pressure and do an idle air volume relearn if you want to take it the extra steps. If you removed the upper plenum when replacing the plugs, I would also be concerned about leaks at the plenum gaskets, especially if you re-used them rather than replace them.

 

Thanks for your response. In my mind, it is impossible that a spark plug change would cause both banks of cats to go bad. Now I have to be like Sherlock Holmes and get to the root cause which may not be simple. This is another reason why the dealers charge $400. Of prime interest is a potential leak in the air plenum. At idle, air leaks are magnified due to low rpm and high engine vacuum. My engine is smoother now with the new plugs and exhibits no roughness. I did a WD-40 spray around the periphery of the plenum and was not able to sense any change in rpm.

More PITA.

 

The plenum gaskets are silicone and "technically" re-usable, but I've seen some at 100,000 miles and they've flattened out to the point where they could compromise sealing. For that reason, I usually replace the plenum gaskets when I pull the intake plenum off. They are available on the aftermarket; I recommend Felpro.