I found this missing vacuum line or open line. Where does it go?? I’ve googled diagrams and can’t decider. Also, I have a p0138 bank 1 o2 sensor 2. With a mild miss at idle.
do I replace the sensor, or is it coil related or possible vacuum leak?







the photos uploaded upside down, but you can see the vacuum line that is open is clipped to the air box from the valve cover (my guess PCV)

 

It’s an Infiniti i30t by the way. 1999

 

That looks like the vent hose from the transmission. If so, it s meant to mount that way.

I haveven a 5 speed, so mine looks different.

 

You have an oxygen sensor issue.

Do a search on you tube, like I just did.
1999 Maxima P-0138 code.

 

With all the tracking I’ve done on mine - I can say definitively that is the transmission vent tube as JVG mentioned. It’s supposed to be exactly where it is without any connections

 

Thanks everyone!! It looked like it was meant to be that way! But I wanted to confirm!!
now I have a bank 1 sensor 2 O2 sensor code

 

you might want to look for the oxygen sensor fuse in the fuse panel under the dashboard. Clean off any oxidation, or replace the fuse. I've had false positive oxy sensor codes. I replaced the indicated oxygen sensors on both sides, but till had codes. Until I cleaned the fuse.

should you still have the code after dealing with the fuse, you probably really do have a bad oxy senser.

Your fuel mileage and performance should increase once both upstream sensors have been replaced. It's worth the expense.

 

its throwing bank 1 and 2 sensor 2 now lol. Think I’m gonna park it and order new o2 sensors and clean throttle body and new spark plugs. Go from there

 

Good call.

 

Be sure to NGK spark plugs. Either the OEM plats or copper will suffice.

 

I can’t get the egr tube off. There is another tube in the way!!!

 

post a photo of what you are talking about.

are you removing the upper intake manifold now?

What is your reason for this task.