Back in the days when cars had no computers it was easier: if you had a vacuum leak the mixture went lean, the idle went up and the exhaust temperature as well. If you did not take care of it the piston would melt ...

But now: the leak causes a lean condition and the fuel trim adjusts, the IAC tries to get the idle stable and all you can tell is the engine runs rough. If you add fuel by means of starter fluid it may cause a rich condition and the fuel trim adjusts.......

Your previous owner may have tried to hook up the brake booster here or he thought he needs that hole for a temperature sensor.

 

I had the same problem. My air duct was cracking and split in between the ribs where it bends. Just gave it the duct tape fix til the new one gets here and then I'll change it. Glad you found the issue

 

My wife's car has the code, it showed up after doing a tune up, found out I had ripped the air intake hose. I replaced that, replaced the fuel pressure regulator solenoid cause I got a code for that, checked all the hoses for a vacuum leak. The thing I can think of is the fuel pressure regulator or the fuel pump.

Thanks in advance!

 

Hey, did you found the fix?

I also have had a cracked hose and have replaced it + the solenoid, but the problem's still there.

cheeks.

 

I don't 100% remember what it was but I ended up running some fuel system cleaner ans replacing the fuel pressure regulator then also replacing both coil plugs before the issue fixed it's self. Good luck

 

I thought the problem was gone after I drove it around a few times (it normally would have thrown the light by then) but after a 45-minute trip on the highway, the light came back on when i got back to stop signs and lights.

 

You simply cycled the engine which the ECU to clear and or reactivate some DTC may take 2-4 complete engine cycles. Or a extended driving period of 45minutes or more.
What you described is the ECU is keeping the DTC (problem) in pending file because it is not yet resolved and will continue to activate and reactivate the check engine light. It also means that your emission monitors are not currently in a positive state. Meaning your emission out the tail pipe may be higher than normal resulting in lower MPG power and can cause eventual damage to your catalytic converter. In any case depending on when you state requires emission testing you may not qualify until you resolve the problem.
As soon as your engine check light is activated that would be the time to check for the DTC that activated it before multiple DTC are activated caused by the initial problem and activation of the first DTC.