First sorry if I'm posting a known issue, but I'm new and didn't see anything quite like my problem. I have an 09 G37 sedan 6mt with just over 21K miles. At about 17K miles the engine light came on. The dealer quickly diagnosed the problem and replaced the evaporator assembly. Then at 20,500 miles the light comes back own. This time it's a multiple misfire code. After 3 days of tests the dealer says it was fluke. They reset the code and send me on my way. Now 500 miles later the light is back on and the car is back at the dealer. The two recent incidents both occurred under the same conditions: the car had been sitting for 3 or 4 days, has a rough start, and then the light is on with 30 seconds of cranking the car. I do use ester oil and only premium fuel. Any ideas? It's really frustrating. I love this car, but I'm ready to dump it and get something reliable.

 

Can you post the DTC's that your getting?

 

I don't actually know numbers sorry. The first was as evap leak and seem sto have been fixed. The recent code is for multiple misfire.

 

P300 again. The dealer just called and said the MAF was causing a lean mixture. MAF was replaced. I hope that's it.

 

Any mods on your car? Intake in particular?