Running a PO133 code---o2 sensor slow to respond. Does that mean it should be replaced and if so where is it?

 

You need to know it's really P0(zero)133. Not PO(OH)133. It makes a difference in trying to do a search for information.

It would indicate that the upstream O2 sensor is getting old and slow and needs to be replaced if you're sure you don't have any vacuum leaks.

Cut and paste from someone else:

"First, you'll need ramps to get the nose of the car up in the air. The two sensors are located on top of the catalytic converter - one at the front, one at the back.

Try the easy method first - I was able to get mine loose with a shot of PB Blaster 10 minutes before I started and one good whack on the socket wrench. If you can't get anything to happen with brute force alone after a few minutes, then it might be time to resort to the torch. My car is a Southern one and hasn't seen much road salt in its life, so there's very little rust anywhere underneath.

The harness for the connectors was the tricky part for me (mine being a turbo with stuff in the way; yours should be slightly easier). It's wedged in the back of the engine behind the transmission. You will have to remove the bracket holding them in from below, and then jump up top and pull the pink/red part away from the black plug part with a screwdriver. Then the plug should simply slide out, but separating the two halves required quite a bit of force.

Are you sure your O2 sensor is bad? 95% of O2-sensor related codes are from vacuum leaks somewhere in the engine bay; if you've eliminated those and are still having problems. then go ahead with the replacement."

If you need to use a torch try to make sure you have MAPP gas (comes in a yellow cylinder). It's hotter than regular propane and makes the job a little easier. I'm a believer in the PB Blaster as I have used that myself on a number of steering and suspension jobs with good results. Lastly you can get a loan of the O2 socket or an O2 socket set from most of the parts stores like Autozone or Oreilly .... Saves you from buying one when you most likely will not need it again or anytime soon. You purchase it to take it out of the store and get a refund upon return. Just make sure you ask for the loaner tool as if you try it with a new socket off the floor they will not take it back.

 

Looking for others who have had this PO133 code.Was it a simple vacuum leak-[which I'm sure on any Volvo it never is] or was it either or both sensors on the cat?Not looking for mechanics 101[the PB Blaster loosening part ],been twirling wrenches for 42 + years now--just looking for 850 Volvo specific advise please.

 

You've been turning wrenches for 42 years and you can't find an O2 sensor? Simple questions get simple answers.

That code is for the pre-cat O2 sensor, like the previous poster said in his third sentence. Just like he said, it most likely indicates a worn out sensor that needs replacing. You could also check for vacuum or exhaust leaks, sensor wiring and connections, and clean the mass air flow sensor and check its operation.

But most likely, you will come back to the sensor being bad, especially if it has not been replaced in some time.

 

No reason to get sarcastic with me there turkey.I'm an excavating contractor who repairs all his own iron, big trucks,and everyday rides, mostly Chevy trucks.Even though I've had several 850s and a 740 and worked on all of them,I'm not into codes and computer related problems like some here I'm sure are.I saw the sensors on the cat--was just looking for confirmation that's all.If you just can't answer what you say is such a simple question without the BS prologue,maybe you should'nt answer at all.

 

Dude you were complaining about a step-by-step repair that answered every question you asked, that somebody took the time to write out for you - you warranted some sarcasm.

 

No,I really wasnt complaining--just pointing out I only needed info on other's experiences.I didn't need the PB blaster or ramps part if you catch my drift.

 

No,I really wasnt complaining--just pointing out I only needed info on other's experiences.I didn't need the PB blaster or ramps part if you catch my drift.I do appreciate kiss4afrogs response,yours not so much.

 

You're welcome. The trick is trying to answer someones question on their level. Some people who ask say ... electrical questions don't even have or know how to use a test light and like you said about not being into "codes" there is the other guy ready to hook up an oscilloscope and wants to know what pattern he should look for. And then the rest of us that are somewhere in between.

It was just a cut and past, it may be more basic than you'd like but try to think of it as being something someone might be researching who is all thumbs and you need to point out and maybe even spell out the basics.

I do my best, but in the end it's free and you get what you pay for

I'd check all the vac lines and connections you can get to and if they look good replace the upstream O2 and you should be good.

 

You are absolutely correct Kiss4aFrog.It can be a serious slope with the unknown factor I will grant you but there's really no need to act high and mighty and to start insulting someone.Thanks again.Going to check for a vacuum leak in a few minutes but knowing Volvo ,I'm sure I will be ordering that sensor today.