I've had a 2010 G37xs for a month and it hasn't acted right since about 10 minutes after driving off the lot. As we were celebrating the purchase at a stop the rpms start going bonkers and the lights start flashing. Check engine light was a po420/po430 which didn't help much. After that randomly the car would lose all acceleration and power at random points then suddenly regain all power at inconvenient dangerous times like in traffic. Shops around here knew nothing and blamed clogged up cats which I replaced with test pipes....no change. Random power loss. Well on a whim I looked at the accordion looking things on the intake and there was a tiny hole covered by dried black electric tape that 3 shops never saw. Bought a pair of red silicone intake pipes but only decided to replace the right intake and keep the OEM left one because it looked fine and the OEM stuff for Infiniti is expensive. Test drove it and saw a big improvement but it was still doing it, only way less. Cleaned maf and throttle bodies....still did it. On a whim I looked at the other accordion and sure enough there's a tiny microscopic hole on the inside ridge. Replaced it and omg.....completely different car. As I first turned it on the car goes bonkers, I reset the idle, pull out the driveway, hammer the gas in sport mode only for the tires to chirp and send me and my wife back into our seats like a roller coaster..... unbelievable difference. The shifting, the power loss, coasting to a stop and having rpms drop like a stone....almost all the phantom problems on this board are completely solved by vacuum/exhaust/intake leaks. I'm still in shock. I bet people sold their cars not knowing a pinhole in their intake is wrecking their car. If you got stock boxes and accordians and you're having weird issues, change them. Trust me.

 

Good work!
I'm glad you solved the issue.

Cracked/split factory intake rubber is starting to be a common issue.

 

Interesting as I was not aware that this had become an issue on our cars. Is the hole[s] noticeable? I have CZP Silicon tubes with K&N drop ins and a reseal of the air ducts which pass through the radiator support, and the car definitely seems to respond well to this combination. I clean my MAF sensors twice a year, but they never appear to have any residual oil on them from the filters.

 

The stock intakes are just old and starting to dry rot. The accordion coupler things are especially prone to developing stealth holes in the ridges that are hard to see. Unfortunately these cars are very touchy about their air/fuel mixtures and the symptoms look like other severe issues.