My 2005 G35 RWD turned 100K this March. (STOCK CAR. NO AFTER MARKET MODS). So as suggested in the service manual, I bought (6) NGK PLFR5A-11 spark plugs.
Did not replace them until recently (more to follow on this below). These are OEM stock plugs, that come pre-gapped 0.044".

Fast Forward to June 2013, CA smog time, SES light turns on, First SES light in 8 years. Code reader said P1283. That's the O2 sensor on Bank 2. Cleared code. Smogged it. Barely passed CA Smog (High on NO). I was busy travelling, so was not able to change the O2 sensor. From time to time the SES would come on and I verified it was P1283. Last week when the SES came on, It was P1283, P1289 and P0300. P1283, P1289 are related to Bank 2 O2 sensor. BTW, I've ordered (2) Bosch 15667 sensors from Amazon. P0300 gave me a heartburn. This is Multiple Cylinder Misfire. However, G did not feel any different, no power loss etc.

So yesterday, I decided to replace the spark plugs since it was time and the car was now at 105K, plus the P0300 code forced me to. (Big Thank You to the member who wrote up an excellent DIY with pictures).

While replacing the sparks found plugs #5 and #6 drenched in oil. Plug #5 had a lot more oil then #6. I cleaned them the best i could. Put everything back together correctly.
I double/triple checked all the connections. Definitely did not swap spark plugs wires. Restarted and idled the car for 15 mins. IDLE was a little rough like before, but this
can be attributed to the Bank 2 o2 sensor that was throwing code P1283 before.

This morning when i started the car the SES light starts blinking. Oh-Oh. P0300 is back. Cleared the fault and drove it slowly to the grocery store. Experienced noticable
loss of power.

Here's my action plan:

1. Expecting the O2 sensors to show up on Tuesday - Replace sensor to solve P1283 & P1289. (I know from reading the other threads, Bank 1 will fail soon too).
This is also a potential cause for the rough idle and potentially P0300

2. Order new valve covers and gaskets and replace them to solve the #5 and #6 spark plug oil pooling problem. This could also be a major contributor to the P0300 issue.
I've read so many threads on this topic. Reading all the comments, My opinion of Infiniti is definitely lower today.

3. I have a 3M throttle body/intake and fuel system cleaner kit. I'm thinking of using that too when the valve covers come off.

There are a lot of experienced G35 owners on this site. Do you guys agree with my action plan? Please let me know if i missed something.

Maintenance History:

1. Regular Oil Changes - 7500miles. Mobil 1 - 5W-30 Full Synthetic Extended Mileage with Mobil M1-108 oil filter
2. Replaced the oil pan gasket and oil cooler gasket. They were leaking engine oil. (Thank You BYTHABAY, Your videos were very helpful)

Driving History:

Single driver for 6 years (Me). 80-100MPH on highways is the extent of my spirited driving.
Now my wife drives it. She's a very careful driver. Always drives speed limit.

Thanks in advance for your help/suggestions.

 

Seems like the right way to go about things. Though I'd skip the 3M cleaner and use NTK O2 sensors. They are a little pricey, but they are the OEM manufacturers of our O2 sensors.v

 

I'd agree with P, go with OEM sensors on our cars. The Gs don't play nice with some aftermarket parts especially sensors and electronic things. As to your comment that you have a lower opinion of Infiniti, remember that your car got to 100K with no issues. In the grand scheme of life the oil consumption issue is more of an annoyance than a catastrophic event, it can be addressed by just adding oil as necessary. All car manufacturers have their issues and while Infiniti has it's share of small common problems (think 03-04 radio issues, coupe window motors, sedan third brake lights, compression rod/lower control arm bushings) on the whole the motors and transmissions are rock solid for many and many thousands of miles. I'm at 116K and counting and have spent less than $500 fixing things that broke other than routine maintenance. I'll take that kind of reliability in a heartbeat.

 

Thanks for the reply P & BlueDream. Do you guys happen to have the NTK/NGK part number for the upstream O2 sensors. I hate to pay $212 each from the dealership.

"NGK 24320 Oxygen Sensor - NGK/NTK Packaging" is what i found on Amazon. They are another $20 more. My only concern is, Do they come with an OE snap-on connector. I would strongly prefer not splicing or soldering wires.

BlueDream, Sorry about the wheels on your car. Just saw the pictures.

 

If you give me a few minutes I will be able to find the part numbers. Yes, they do come with the OEM connector.

 

NTK 24404 and 24408 are your downstream sensors. I can't remember if the 05 is fitted with a wideband sensor or not, but that part number is 24320.

Are you sure it is the upstream sensor you need? That number is 24401.

 

Yes i need the upstream sensors. The P1283 and P1289 codes refer to Bank 2 Sensor 1, which i believe are the upstream sensors. Part 24401 is not coming up as a suitable match on the amazon auto parts verifier. 24320 is a good part# for the upstream sensors. Am i missing something here?

My throttle plate has a decent amount of carbon deposits on it. Never cleaned it since i bought the car in 2005. Any particular reason as to why you've suggested avoiding the 3M cleaner.

 

I just put on denso o2 sensors when I put art pipes on and they have done fine, they fit perfect no problems
I got them from rockauto

 

So I was able to work on the G. I replaced the upstream O2 sensor. I used Bosch #15667 for $68. Works perfectly. No connector mods required.

I took the new spark plugs out to check them.I strongly recommend applying the lowest possible amount of anti-seize (I used Permatex). I applied less than 2mm glob and evenly coated the top 4 threads. That was too much! The anti-seize spreads everywhere. I suggest applying the anti-seize and wiping the threads down. That should leave enough anti-seize residue.

Took the spark plugs out. Cleaned the spark plug wells. Cleaned the ignition coils for 5&6. Replaced the spark plugs. Cleared Air-Fuel Mixture Self Learning.

P1283, P1289 & P0300 all gone. Drove 1000 miles in the last 8 days. No problems.

No Valve Cover Replacement! Woohoo!!!

 

ngk says u dont need to put antiseize. check their site

wat do u mean no valove cover replacement?

 

If you were leaking oil into the spark plug holes, chances are that cover will need to be replaced.

Make sure you check after a period of time has gone by to confirm no more oil is leaking,

 

One of the members had a nice DIY on spark plug replacement. He used a little bit of anti-seize. I did the same. That didn't work out too well for me.

My spark plug wells on #5 & #6 had oil in them when i was replacing the spark plugs at 105K. There are a few hundred G users on different forums that experienced the same issue. They replaced the valve covers to stop the oil from pooling in the wells. I just cleaned the plug wells and ignition coils and my P0300 code is gone. I didnt have to replace the valve covers. I dont intend on removing the spark plugs for another 100K.

 

lol wtf?

 

Aren't you questioning how the oil got on the spark plugs?

 

I think that is what he is saying.

No worries. He will need to touch them soon when he is forced to replace coil #5 and #6 when they short out causing misfire code P0305/P0306/P0300. And then hopefully he will replace the VC otherwise this will just happen again. Each coil goes for maybe $50-200 pending on source.

How much are VC nowadays? $200 ish?


COngrats on the 100k!!!! I should be there in about 2 years.