Hi all,
need help with this problem. I have an 09 g37 coupe with 139k miles. While I was driving home from work my check engine light came on and I lost all power while going 60mph. The motor was still on, but the gas pedal wasn't responding. It's as if the car just shut down completely. I pulled over, shut it off, and tried to turn it on again and engine would sputter. Eventually after the third try, it started back up and drove home.

The cel codes are p0138 and p0139 throttle body actuator. Do I need to replace the throttle body? The codes are two different parts, which do I replace?

Thanks for any help you can provide.

 

Could be. But could also be as easy as just needing to clean the throttle body.

 

Check your mass air flow sensor and throttle position sensor a dirty throttle body won't do that. If you have a code reader it will help narrow it down

 

The code that came up was p0138 p0139

 

Anyone else have any info?

 

O2 sensor so check your maf sensor the o2 is seeing rich af mixture. Also check vacuum lines

 

Check engine light has now turned off and car is driving fine now.. I didn't replace anything. I'm sure the issue is going to come back...


any ideas on what I should do?

 

They said what to do.
Clean mafs
Clean Tv's
Check for pcv leaks.

 

Did you recently put on an intake if so recheck vacuum lines

 

Just had the same problem on the highway today. I have a '08, was cruising around 75 mph and all of a sudden the engine was not responding to throttle input. I downshifted and the car came back online. Than within another mile or two it did the same thing. Drove it back home about 30 miles no additional issues. I checked no codes. I'm going to clean the MAFS tomorrow.

 

Brought the car into the dealership today to attempt to identify the stall problem with the car. Nothing found, everything is up to spec. The service manager began to tell me that the mechanic really put the pedal down and then he realized he was talking to the customer. He than said, he wanted to duplicate the problem. They ran me off an report and told me that I needed a power steering system service for $179.00, new spark plugs $450.00, and new valve cover gaskets on both banks $750.00. I told him that I just did the spark plugs and the PS fluid flush 10K miles ago (thanks to this website). They also wanted to perform an alignment for $120.00. My tires were installed 20K miles ago and I had an alignment done then. I'll bring it back to have it checked. On the valve cover gasket leak, he said it wasn't really a leak, but a small seepage. Anyhow that's my story. Bottom line is if there is no codes stored or lights on, they can't tell you anything that your OBDII reader doesn't provide, with the exception of a fishing expedition for additional maintenance.

 

They couldn't find a real problem so they invented a few for you to choose from. Find a different dealer, or go to an independent.

 

I just checked my PS fluid, it looks like it just came out of the bottle. They told me that it was contaminated and dirty. You are right, never go to the dealership.