Hello All, I am the proud owner of two volvos and on my elder model with 137,000 just replaced spark plugs and some o2 sensors, and cleaned throttle body, cleaned mass airflow sensor, trying to make the code (PO507) go away so can pass the smog. The code appeared even before I cleaned the throttle body and MAS sensor. I have also tried a "idle relearn" process, (warm up), 1 minute N, 1 minute D, and accelerate through the gears and back down. The RPM is over 1100 in park/neutral and about 950 in gear. but still comes back after awhile. I almost got the car to pass the smog with the exception of that code remaining present. Anyone have some other suggestions?
Much appreciated.

 

vacuum leak. Be sure to clear all codes. If its a hard set code, do a Hard Battery Reset.

 

Check the small 1" diameter (or so) rubber hose near the throttle body that connects to the front intercooler. It has been known to break causing various idle and running issues.

 

I have tried the battery Hard reset twice and checked the hoses for leaks/cracks. I even took a can of carb cleaner spraying it around the hoses and throttle when the engine was running to see if could get a reaction. That is what i read could help narrow down where the leak could be.

The code disappears and then goes away. There is some oil leakage appearing on top of the head. Could this mean anything related to the idle?

I did actually have the P0133 O2 sensor codes reappear after I sprayed the carb cleaner so maybe there is a leak? I had changed the o2 sensors about same time I did the plugs so i dont think they could be bad so soon?

Do you think it could be the throttle position sensor out of whack?

Thanks again for your help,

 

Is the idle adjustment screw in too far? It's on the outside of the throttle body.
P0133 in my case was caused by a faulty o2 sensor. I just had a lot of trouble with this code - My o2 sensor went bad and I bought a new one. Code stayed. Turns out that I needed a new oem o2 sensor. The one I bought from eBay was no good for the car.

 

Here is a pic of the hose I was talking about. It's attached to the intercooler.

 

Where could I get a replacement hose for that right there ?? Exact hose can't find anywhere

 

I believe I bought mine at the dealer. Because the two ends are so different in size a generic hose won't work. I can't remember how much it cost though.