O2 sensor replacement - ambitious for newbie?
 

My car is hunting at idle and I spoke to a mechanic and he suggested that the O2 sensor should be replaced. I do not have experience with fixing cars however I am very keen to learn and have had no trouble picking up other skills (eg home renos). It looks like the sensor replacement is pretty straightforward. Is this a reasonable thing for me to try?

Cheers

Pretty easy but the sensor can be tough to get out depending on how long it's been there. My 95 911 came out pretty easy but the 89 944 required the exhaust to come off so I could get a BIG wrench on it.

+1. It could be easy or hard depending on how seized the sensor is into the exhaust. Give it a try and if you can't get it, then you can take it in to someone. Won't hurt to try.

Not sure if spraying penetrating oil on an O2 sensor would damage the sensor at all, hopefully someone else can chime in on that. I guess if you are replacing it with a new one anyone then it won't hurt. Soak it with the exhaust cold for a day or so, several applications, then give it a try. PB-Blaster is my penetrating oil of choice, available at your FLAPS.

.that's internet car forum speak for "Friendly Local Auto Parts Store" for a NooB. :)

Hello fellow canuck (and briefly a "Pegger" actually),

An O2 sensor change is a sinch, I did one for the first time yesterday. I ended up using one of the less expensive alternative sensors and it seems to work fine. The engine runs well and no more idle fluxuation. I used the NGK 22014 available at NAPA for $70.00. To get a none Porsche sensor to work you will have to splice in the new three wire sensor to the old 911 plug.

Replace the old and new sensor using a 22m wrench. Mine was a little tight so I soaked with penetrant oil overnight and it came off just fine the next day. Just remove the left rear wheel and there is easy access. The three wire plug is on the left side of the engine compartment.

Thanks guys. I think I will give it a go.

Pelican offers a "universal" O2 sensor for $71 and another for $134. What's the difference? Both are made by Bosch.

I really want to become hands-on with my 911.

Cheers

Ps - Nick, thanks for the noob translation!

the more expensive one is a plug and play. just disconnect the plug in the engine compartment by the fuel filter. the cheaper one is the one you have to splice. advanced auto online has the bosch plug and play for $93 shipped and no tax. i just did mine with a cat delete.

If you are serious about this, don't spend the $$ for the fancy O2 sensor.

Buy the universal Bosch and with the money saved drive to an electrical supply store and spring $20 for a set of Channel Lock wire strippers and ask them to provide you with crimp connectors. Better yet, solder the wires together and get some shrink wrap tubing to seal off the connections.

Also, buy a nice digital multi-meter. You don't need a Fluke but a spend north of $75 will get you a solid tool you will not be able to live without.

Watch youtube videos on how to use a multi-meter. It ain't rocket science but you don't know what you don't know.

http://www.quill.com/channellock-wire-strippers/cbs/257355.html?Effort_Code=901&Find_Number=701079ORS& promoCode=460460055

I think the sensor wires can not be reliably soldered. IIRC, either the heater or sensor wires must be crimped.

Hunting idle can be caused by so many things.

I wish I knew 'lectricity better.

Ack! Sorry, I want to clarify that some of the wires are steel. I just can't recall which ones. I think it's the two heater wires that need to be crimped.

Thanks for the additional input. I realize that I have a *lot* to learn. To get started I think I would prefer an easy approach just to get my feet wet.

Rusnak - I've read a number of threads on hunting during idle and I realize that there could be other reasons why that's occurring. I thought this would be a reasonable place to start. I may come back for more advice!

Thanks again.

You can buy a Bosch three wire O2 sensor for a 96 Ford Taurus at your local FLAPS for less than $20. Cut of the connector and splice that into you existing engine side connector. Crimp and heat shrink. No solder.

Stagger your crimps so you don't have them in a big lump and you can reuse the factory protective sleeve.

Lay the new and old sensors out on the bench when you make your cuts to keep your overall length close to factory. Use a little soap or windex to lube the grommet and it will slip into the engine tin easier.

Some of the aftermarket pre-mufflers move the O2 bung further away from the hole in the engine tin. If you are headed that direction now is the time to add a couple of inches to the bottom half of the harness.

-J

Was serious above - no sarchasm. So much I don't know about cars and their electrics.

When I find a problem that seems complex, it ends up being brutally simple. But in this case I assumed it was simple and there is more to it. i.e., Different type of wire. (My 81 still has the single wire)

Also, when I wrote the above I was thinking about my cyl head temp sensor I installed on my 81 and how you are not supposed to shorten the leads to the dash gauge. My immediate thought was that some of the wires in a three wire sensor might be based on that principle - (resistance?)

I often fix cars for folks that have O2 problems and I still have not taken the time to really study the more modern systems so I can test them effectively. I have been lucky and not wasted money on one I did not need to buy but it usually came at the cost of eliminating other variables - which is costly.

So any-hoo....Sorry Colin, for rambling. Do take time to study the basics on a multi-meter. It will be your new best friend. If you couple the knowledge with info you can gain here through searches you can be a fixin' stud. It is really gratifying to nail a gremlin through diagnostics.

Make sure your O2 sensor is really the root of your hunting problem. If you disconnect it and your car stops hunting, then the sensor is the problem and needs to be replaced. If it still hunts after disconnecting, it might be your fuel mixture and you need a CO analyzer for that.

Another easy way is to use a hacksaw or zizzwheel, cut the sensor flush with the nut and use a deep socket. 22MM or 7/8. You can get a lot more torque on it that way.

http://www.clarks-garage.com/shop-manual/OxygenSensorInstall.pdf this might help, not your exact application but you should figure it out

Mine was a little tight so I soaked with penetrant oil overnight and it came off just fine the next day.http://www.sioauxzc.info/5b.jpg

If you have a hunting idle, I'd suggest checking for vacuum leaks first. Vacuum hose is pretty cheap, so it certainly wouldn't hurt to replace if it doesn't flex easily or is cracking.

O2 sensor replacement is easy. Jack up the driver's side of the car, 22mm wrench. The universal O2 sensors are a cheaper way to go, but solder the connections with silver solder. The universal Bosch sensors come with this Posi-lock box looking thing, but it's given me trouble in the past.

Thanks for the input. I'm certainly going to consider all of your comments.

Bob - no worries about rambling. I'm lecturing a genetics course right now and my students could verify that I ramble pretty regularly!

Cheers

I've spent untold hours reading threads in this forum over the past few years. I've had my '84 since December and have been reading here even more since buying it, soaking up the vast amounts of knowledge and experience. My mechanic buddy and I did the 60K service and the O2 sensor at that time. (Sensor replacement called for every 60K miles.) My idle hunt (slight) and slight 'jerky' issues seem to have been cured by replacing the intake gaskets and spacers. My buddy squirted water around the intakes and sure enough, the idle stumbled on one port. New gaskets and spacers seem to have done the trick in my case. For now! Runs and drives like a dream.

Oh, and I have the Pelican O2 sensor tool but I seem to think that it wasn't needed when I removed the original. Car on stands, LR wheel off, heat shielding removed and it was right there and easy to remove. hardest part on my car was the broken upper O2 sensor plug which may not be a problem on your year.