Hey everyone. So I just bought a 2011 g37x sedan with 75k. It ran and drove fine in the test drive but a few days after the purchase stuff started to get weird. First I noticed that the idle was pretty low sitting in traffic. It was about 450 -500 and would occasionally dip lower and almost stall, then pick back up again. Soon after noticing this I got an SES light for p2a03 and p0420 I looked up the codes and researched in the forums. First thing I tried was cleaning the MAF and throttle bodies. So I picked up new air filters, maf cleaner did a bunch of cleaning. ( I did move the butterfly valve on the TB very carefully to clean around it). The MAF and TBs were pretty dirty! So once done I buttoned everything back up and did the ECU reset with the pedal and all the weird timings of steps. Okay, idle is about 100rpm improved and so it throttle response. But about 35 miles later. The SES came back on. This time it was p2a03 and p0113. I still need to check for exhasut leaks but I'm getting bad gas mileage (13 mpg in traffic) so I'm guessing that AF sensor is bad. But none of this explains why I got the p0113 code. Is there another TB reset procedure I should do ? Is one code causing the rest of the codes ? Any help would be greatly appreciated. Thanks guys

 

If you moved the throttle with the battery connected, you cause problems. I would disconnect the battery for a couple of hours. Reconnect it then start the car; if you're still getting codes, then more research is needed.

 

I disconnected the battery before touching anything. Then once it was all done, I reconnected the battery

 

Check the vacuum lines

 

That was the first thing I tried before all of this. I started the car and went around spraying some cleaner and listened for a change in idle. I couldn't find anything. I also inspected are intake tubes and seal, those seemed fine , as well as TB o-ring

 

You sure you dont have tear in intake accordion pipe section

 

I inspected them when i removed them for cleaning. I didnt see any cracks or tears. But it was really just a visual inspection, i didnt do any sort of crazy pressure test.

 

Take it out and fill with water or use smoke tester