i have 2007 g35 with a vq35hr that the p0300 code wont leave me alone. I've already changed the coil packs, spark plugs and checked to see if there was any oil in the spark plugs tube there wasn't any I'm at a lost next thing up will be test pipes to see maybe if the cat is clogged. I'm putting a link to the video that show how my car sounds any input would help, thank you in advance.

 

Have you ever thought of reading the FSM?

I find it amazing of the lack of the use of "search" prior to asking for assistance

http://www.nicoclub.com/service-manu...7_G35_Sedan/ec

See page EC-245

P0300
Multiple cylinder misfire detected
Multiple cylinder misfire.
• Improper spark plug
• Insufficient compression
• Incorrect fuel pressure
• The fuel injector circuit is open or shorted
• Fuel injector
• Intake air leak
• The ignition signal circuit is open or shorted
• Lack of fuel
• Signal plate
• A/F sensor 1
• Incorrect PCV hose connection

After checking all of the above report back and let us know what the root cause was

Telcoman

 

You should at least read the FSM or search before throwing parts and money at your car. Swapping plugs and coils due to a trouble code is not the way you should proceed.

I'd buy a scan tool that can read live data. Let the car get up to operating temperature and look at your long-term/short-term fuel trims. If your car is having to add fuel then look for a vacuum leak and if it's taking fuel away look at the fuel pump, injectors, etc.. (test them don't just swap them out).

You can use unlit propane around the engine bay to see if the RPM changes looking for a vacuum leak. Easiest thing would be to build a smoke machine or have your car smoke tested to see if there are any leaks.

Check all your hoses for cracks.