Replacing O2 sensors

[Bala]

Trying to replace couple of O2 sensors that are reporting errors. It is so tight and hard to remove. Don't want to end up breaking anything. And don't want to use any penetrating oil that might cause headaches later.

Also need advice on using the existing connector and attaching the new sensor wires as they don't have the connector. Should I use the something specific like posi waterproof connectors?

Advice appreciated. Thanks.

[Burg Boxster]

I guess first question is why are you replacing "a couple" of O2 sensors? Rarely does more than one O2 sensor go out at a time. More likely you have MAF issues (as I think you already know based on other posts) or a vacuum leak... both often disguise as O2 sensor problems. Did you test the sensors w/ a multimeter to ensure they are bad?

Penetrating oil is fine to use.. just keep it off the new sensors and it will help if the car is warm.

Good luck

[JAAY]

My Bosch napa sensors came with water tight buildable connectors. They look like little black boxes.

[Bala]

Originally Posted by Burg Boxster

I guess first question is why are you replacing "a couple" of O2 sensors? Rarely does more than one O2 sensor go out at a time. More likely you have MAF issues (as I think you already know based on other posts) or a vacuum leak... both often disguise as O2 sensor problems. Did you test the sensors w/ a multimeter to ensure they are bad?

Penetrating oil is fine to use.. just keep it off the new sensors and it will help if the car is warm.

Good luck

Durametric reported the sensors (one on bank 1 and the other on cylinder 4-6. I looked at them both and one was totally swamped with oil which I cleaned out but think it might have done something. The other was molested by PO as the connecting wire is almost a foot long. I'm not kidding!

The o2 errors were there even before the MAF issue surfaced.

[Bala]

Originally Posted by JAAY

My Bosch napa sensors came with water tight buildable connectors. They look like little black boxes.

I went with parts train ones. If I'm filling up the money pit I might as well fill up a little at a time!

[Ghostrider 310]

bala, I sprung for the Napa O2 sensor socket which is actually just a socket with a wire accommodation slot running parallel with said socket. I never used it sold the car but like you I found moving an O2 sensor tough if not impossible with an end wrench...

[Bala]

Unfortunately I have to install myself as they need to be wired with the old connector. I think the mechanic shops would take my arm and a leg. I have only one set left since buying this car!!

Question though: can I use the air impact wrench (only to unscrew)? Am I asking for trouble?

[Burg Boxster]

I think you are asking for trouble as install torque is only 22# IIRC. You need to break the corrosion w/o damaging. New cats or r&r the headers will be more expensive and/or more hassle facing even more corroded bolts... Instead, use PB Blaster or the like to hopefully penetrate. Hit it a number times and maybe let sit overnight or for a day or two. Also, if you have an advance auto nearby, they have a loaner program for the O2 tools. Basically, you buy the kit which has 3 options... crowfoot socket and two others. You use and then return w/in 30 days and get full refund. I used it this summer and it was only $30 which I got all back when i returned the set 2 weeks later.

Good luck

[Bala]

Thanks Burg.

[healthservices]

I removed them on both my boxsters and they do not need the O2 socket (though I have several) 7/8 wrench is all I needed.

I bought some cheap $50 ones from Ebay and they suck big time. I think they are wired wrong.

I then bought some Bosch ones that I had to reuse the original connector. I had absolutely no problems with those, wiring or re plugging them in.

[mikefocke]

Muffler shops charge $49.95 in my city to replace a O2 sensor that has the pigtail/connector. 6 months ago did it for my Boxster and in the same week for my CRV. Same charge.

If you have oil in there, you have more serious problems and are just wasting $ until you sort out the big problem (AOS, rings, ??)

I do recommend the Bosch ones with the pre-installed wires and connectors as the connection must be done by crimping or it gives false readings. And the Bosch people use robot machines and test afterwards to make sure the things are done right. I've seen too many horror stories from the cheap sensors to try and save the few dollars.

Cross reference of part numbers on my O2 sensors web page.

[Bala]

Replaced O2 sensor on bank 2 ahead of cat. The "P0150: Porsche fault code 18 - O2 sensor ahead of cat. conv. Cylinder (4-6)" went away.

The other error still persists. "P0130 Porsche fault code 10 - O2 sensor ahead of cat. conv. Cylinder (1-3) Signal Implausible.

Does this point to a failed sensor?

[Bala]

Originally Posted by mikefocke

Muffler shops charge $49.95 in my city to replace a O2 sensor that has the pigtail/connector. 6 months ago did it for my Boxster and in the same week for my CRV. Same charge.

If you have oil in there, you have more serious problems and are just wasting $ until you sort out the big problem (AOS, rings, ??)

I do recommend the Bosch ones with the pre-installed wires and connectors as the connection must be done by crimping or it gives false readings. And the Bosch people use robot machines and test afterwards to make sure the things are done right. I've seen too many horror stories from the cheap sensors to try and save the few dollars.

Cross reference of part numbers on my O2 sensors web page.

Mike,
Thanks for the input but I bought this car knowing it had some issues. So have a list of things to fix and don't want to go genuine given the costs. I feel some things aftermarket is worth a try, IMHO. Some things I already know will cause issues if taken the aftermarket way. Also it is a pretty simple part and don't think someone other than Bosch would not be able to get it right. Think it would be worth a try given the low price. If it doesn't then put in OEM ones.

I crimped it and taped the replacement one well and it seems to be working. I cleaned the MAF again. Now on to the next O2 error.

I ordered a replacement for my AOS tube that broke. I will take a closer look at the AOS again when replacing the tube. A new one is on the way anyway and if it looks like its oiled badly I shall replace it. That I ordered genuine.

[Bala]

Originally Posted by Burg Boxster

use PB Blaster or the like to hopefully penetrate. Hit it a number times and maybe let sit overnight or for a day or two. Also, if you have an advance auto nearby, they have a loaner program for the O2 tools.

Good luck

Burg,
Thanks for the tip. Worked out great. Used some penetrating oil on the thread, heated up the cat side around the O2 with a heat gun, got the rental from Advance and worked like a charm.

[Topless]

Originally Posted by mikefocke

Muffler shops charge $49.95 in my city to replace a O2 sensor that has the pigtail/connector. 6 months ago did it for my Boxster and in the same week for my CRV. Same charge.

If you have oil in there, you have more serious problems and are just wasting $ until you sort out the big problem (AOS, rings, ??)

I do recommend the Bosch ones with the pre-installed wires and connectors as the connection must be done by crimping or it gives false readings. And the Bosch people use robot machines and test afterwards to make sure the things are done right. I've seen too many horror stories from the cheap sensors to try and save the few dollars.

Cross reference of part numbers on my O2 sensors web page.

This is excellent advice Mike. +1

[mikefocke]

A P0130 can be
– Oxygen sensor
– Wiring harness
– DME control module

So the flow chart suggests first testing with another O2 sensor and if the problem persists, then checking the wiring.

[Bala]

Originally Posted by mikefocke

A P0130 can be
– Oxygen sensor
– Wiring harness
– DME control module

So the flow chart suggests first testing with another O2 sensor and if the problem persists, then checking the wiring.

Where can I find the flow charts? That would be a wonderful tool.

[Bala]

Update:

Got O2 sensors from Parts Train, crimped them onto the old connector for Bank 2 pre cat. Put them in and error code disappeared. Tested with Durametric and all seem ok for bank 2. Bank 1's P0130 persisted. So, swapped sensors from Bank 2 to bank 1 and vice versa. Bank 2's P0130 went away and Bank 1 was reporting P0150. So, replaced the one that was reporting error with new one from Partstrain and all is well. No error codes.

Looks like I can now get my darn inspection done. However, the "Ready Status" screen shows Fail for all (Cat conv, Fuel Tank ventilation, Secondary air system, Oxygen sensors, Oxygen sensor heater). These values don't go away until the car is driven for a few miles? Does this show up as failure on the DMV inspection? What is the Ready Status screen and it's purpose anyway?

[Burg Boxster]

Yes, Ready Status not being ready will show up as a failure for DMV emissions... in my state at least and many others that I know of so I suspect NY is same.

Purpose is to ensure the emissions system is functioning correctly... otherwise one could just clear codes and/or CEL right before testing and subsequently pass before failure is noted again by sensors and DME.

The Ready Status will change after some regular driving... can't recall exactly the time/distance parameters. Otherwise, somewhere in the archives here there is a specific driving procedure (something like 35MPH constant for X blah blah blah...) to get it to change to ready quickly.

Good luck and glad you're making good progress

[Bala]

Found the thread on cycling for ready status. Will have to do it in the dead of night under cover!!!