Finally replaced all 4 O2 sensors w/ generics for $160.
 

I know I brought this up about 8 months ago and I finally got around to doing it. I went to Parts Train and ordered 4 US Auto Parts Network 4 wire universal sensors for $156 including shipping and I picked up two 8-pair packs of weather proof connectors. I pulled the old sensors out and cut the plug ends off about 6" down the wire. I put the connectors on the wires and plugged them together and plugged the sensors back into the car. Since I put the weatherproof connectors on, next time I only have to put female connectors on a new sensor and plug it in.

They have been running beautifully for the past 2K miles and I'll report back as they age. It sure was nice to replace all 4 sensors for the price of 1 of the exact replacement sensors. :cheers:

Did you happen to take pictures along the way as you bought and rewired everything?

GOT DAMN! all 4 sensors for only 156 total...did you use that heat shrink wrap stuff to insolate them?

You need to post pics on which wires to which wires or do a detailed write up. This could save everyone 300 bucks or so.

I did use the heat shrink and took pics that I can post once I get them off the camera. I will try to post it on my website too asap, but really busy right now with work and other obligations.

For the wiring, it's very easy since the universal sensor has the same wiring colors as the old sensor. I just wired black to black, gray to gray and the two whites to the two whites. The two white wires are interchangable so it doesn't matter which way you wire those two. I also used some of the plastic wire shielding to protect the connectors from the heat. It's the tubing that looks corrogated with a slit down the side that is used to bundle wires together.

Btw, you can't search for the Porsche Boxster O2 sensor and find it. The part number is USOS-4000 and you will usually find it listed under Lexus and Audi vehicles. I found them Speedy Auto Parts for $34.64 each so it's even better. :cheers:

Nice, I dont need anymore info. Thats all I need, thanks. If they are working well Im doing it myself. Actually is there a difference between pre-cat and post cat 02 sensors?

Nope. The only difference in the original ones is the connector plug on the end of the sensor. If you look up the Bosch universal sensor for Boxsters (about $100 ea) the same part number is for pre and post cats. In fact, any 4-wire sensor that physically matches the screw threads should work fine.

Can't figure out how to order that part
 

Parts Train doesn't seem to come up with any way to select a generic part like you describe from their web site. Clicking on Oxygen sensors only prings you to a menu that asks for your car's specifics and, for a Porsche Boxster 01 3.2, that only leads to the Porsche specific part with pigtail attached at $156.

Can you tell us how you found this part? And how you figured out it was the right part # considering that there are 4 O2 sensors that are listed?

Go 4 posts back. I found them at another place (Speedy Auto Parts) for an even better price. I also list the part number if you want to look around for them.

http://www.partstrain.com/products/AutoBody/Catalytic_Converters/1999~PORSCHE~BOXSTER~6~2.5~986--001.html



Right here ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

so the sensor is physically the same? it just screws right in to the old socket? this sounds too good to be true

Well, I was just going to buy 4 of them and a new maf but I went to check out and the shipping was $35.00 give me a break! I went online with a live customer service chat and they still wouldnt budge. They lost a 400.00 plus sale over greedy and inflated shipping. That was Parts train by the way. Im going to check the other site now. If thety dont try to rip me off I will order from they.

All O2 sensors are basically the same. They give a reading to the DME in milli-amps (IIRC) based on the temperature of the cats and the DME adjusts fuel/air mix depending on that reading. The only difference between O2 sensors is the number of wires. I believe they are all the same physical size, but I'd rather be cautious and make sure you check the threads before you just go out and get them. I also bought a Bosch universal sensor from someone on eBay that's made for the Honda Civic for $15. It matches my original sensors too.

Holy cow! The shipping I paid was around $15. I thought it was high at the time, but still so much less than the regular ones I took the deal. I never checked their MAF price. Is it pretty good too? I paid $245 for an MAF at Sunset so I'm interested in the differences.

I ended up buying an 02 sensor from speedy auto parts, just one. I tried everything I could to buy four but it just kept going back to one in my shopping cart. My scanner says I have one bad 02 sensor so I will just start with that one. Bought the MAF from Pelican for 280.00 and free shipping I trust them.

ohioboxster,

How can you tell out of the 2 which sensor needs to be replaced?

My CEL came on last week with a P1117. It hasn't come back on TG.
I'm hoping it doesn't but if it does I am going to pay 147.00 for a Bosch sensor. From thiis website
http://www.automedicsupply.com/index.php?&model=Boxster&stopredirect=yes&width=10 24&height=768

Hi,

Using Universal O² Sensors isn't an issue if you do your homework. There are 5 types of O² Sensors; Unheated Thimble-type O² Sensors (LS), Heated Thimble-type O² Sensors (LSH) , Heated Titania-type O² Sensors, Heated Planar-type O² Sensors (LSF), and Heated Wide-Band O² Sensors (LSU).

Further within these types, several different primary materials are used and two different methods of extrapolating the Air/Fuel Mix are used.

A sensor using Titania, changes it’s resistance of a reference voltage (sent to it by the ECU) which will change proportionally to the amount of Oxygen it is exposed to. This technology was never in widespread use and was found only on a few cars from the mid-80’s to mid-90’s. It is estimated that fewer than 3% of all cars and trucks use this type.

The most prevalent types of O² sensors on the Market are those which use a ceramic made of Zirconia. When exposed to Oxygen (O²), a Zirconia ceramic will produce a voltage proportional to the amount of Oxygen it is immersed in (Exhaust stream) as the Oxygen molecules embed into the ceramic’s surface. For the two types of Zirconia sensors, they need to be heated to 650°F. This further breaks them into two additional categories: Unheated and Heated.

Unheated Zirconia sensors generally have only one or two wires. Their advantage is that they are simpler to manufacture and are of the earliest technology. Their disadvantages are that they contaminate sooner (as carbon and other combustion by-products condense on the exposed ceramic) and on Cold Starts, don't allow the ECU to function until the exhaust gasses bring them up to their operating temperature (Open Loop). Also, if idling for extended periods, they can fall below their operating temperature threshold (650°F) and force the Car's ECU back into an Open Loop where the ECU is no longer monitoring or responding to changes in the A/F mix. This affects both emissions and performance.

Heated Sensors contain a Heat Coil which is fed by a separate voltage circuit and usually have 3 or 4 wires. Their advantages are that they come up to temperature sooner and don't stop monitoring at idle. Also, since they are heated, fewer contaminates can condense on the ceramic surface of the sensor giving them a longer service life.

Heated Planar-type O² Sensors (LSF) and Heated Wide-Band O² Sensors (LSU) are a much more modern technology and are used primarily on only the latest model cars. They use a circuit board with the sensors attached and use a pulse-width heater coil. Their advantages are that they operate at much higher temps (1292° to 1472° F) and will vary their voltages in much smaller increments allowing for direct sampling of the A/F mix instead of an extrapolation method used on the other types of sensors. I won’t discuss these in-depth except to say that the ’08 997TT uses the Heated Wide-Band O² Sensors (LSU) type. Hope this helps.

Zirconia O² sensors are the type used on the Boxster (Heated Thimble-type O² Sensors (LSH)). Because all air does not contain the same amount of Oxygen (changes in altitude, Ground Level in Stop & Go Traffic, etc.), Zirconia sensors also need to sample reference air. To do this, they either have a hole at the base of the detector, or sample air drawn-in from the electrical connector and sent to the sensor inside the wire sheathing.

This is where most people trying to use Universal Sensors will get into trouble. They will inadvertently block the reference air from the sensor by using the wrong connectors (which contain no sampling hole), kinking the sheathing, or by using heat shrink tubing and also blocking the sampling hole. When using Universal sensors, you need to carefully examine the new and old sensors. If the sampling hole is in the sensor body, there will be no problem. But, if the reference air sample is drawn into the connector, you need to make sure that you don’t interfere with this function when attaching a connector. The Bungs for O² sensors are standard, so virtually any Universal will work so long as you account for the air sampling to occur.

O² sensors have a usable life of only about 30k mi. (source: Robert Bosch, AG). After this, range (MPG), emissions, and performance can suffer. Changing them at this interval is one way to breathe new life back into your car and the cost is significantly offset by fuel savings. You should change all the O² sensors at the same time as they are mileage dependent. You can confuse the ECU (DME in Porsche parlance) by mixing new/old sensors causing a loss of range or performance. And, if you have 1 bad one, you'll soon see the others fail as well, especially if over 30k mi. of service, so it's just generally easier to do them all at once (save on S/H, installation, etc.). Hope this helps…

Happy Motoring!... Jim’99

P1117 is the code for the maf sensor, I used an Atron hand held scanner that I bought off of e-bay for $55.00 it comes with a code cd,will turn off the cel but wont give actual information about sensor like voltages and such

Ohioboxster, are you sure?
I thought P1117 code refers to the Precatalyst oxgen sensor. This infomation is from Bentley Service Manual.

MNBoxster you must like to type alot, unless you like using copy/paste.
thanks for the lenghty email but what you wrote how does that answer my question.

?-
How can you tell out of the which sensor needs to be replaced?

Sorry, I just punched the code in my program and it said " Manfacturer control fuel air metering" If you hook a scanner up to the OBD II port under the drivers side dash it will tell you which 02 sensor is bad. One of the guys on the forum informed me Auto Zone will scan the car for free. You could buy one of these , thats what I did.

http://cgi.ebay.com/Actron-Code-Reader-CP-9135-OBD-2_W0QQitemZ260036047969QQihZ016QQcategoryZ92078QQr dZ1QQcmdZViewItem

I bought one for 55 bucks so it worth it to look around on e-bay.

Hi,

You have a 2.7 e-gas Boxster while OHBoxster has the 2.5 non-e-gas model. Different code definitions for each.

But, a Bad O² sensor can throw one of many codes, usually all related to AF Mix, ECU, or actual O² sensor.

If you read my reply, and if your Boxster has 30k+ mi. on it, you'd see that you need to replace all the sensors, not just the one which is showing itself to be faulty at present. These have a Service Interval which is mileage dependent (30k mi. according to Robert Bosch, AG), just like your Oil & Filter, and they all have been in service the same amount of time/#miles .

You should replace them all at once. Not doing so may lead to no improvement in performance/range/emissions (you might not even feel a difference, but the DME may not be selecting the optimal Maps for your car/gas/driving conditions). And, you'll most likely be starting down a path where the other three require attention in short order...

Happy Motoring!... Jim'99

Jim,
I used his cars information when I punched it into mt DTC look up software.

Hi,

OK, my misunderstanding. But, your code description is still in keeping with bad O² sensors. If the signal from the sensor is non-existent, then a code speaking directly to the sensor will be thrown.

But, if the sensor is sending signals which are outside what the DME has been programmed to expect, it gets confused. It doesn't fault the O² sensor because it is getting a signal from it. But, it can't find any Maps to use which correspond to the signal values from the sensor, so it will code that the DME (Mfr. AF Metering) cannot function properly because that's all it knows, it doesn't know the O² is bad since it is getting an actual signal from it. An O² sensor can fail outright or it can fail progressively, sending signal values (voltages) which the DME has not been programmed to identify or interpret.

In this specific case, it could actually be one bad O² sensor, or any/all of them, which is one reason you want to change them all at the same time. They're not like lightbulbs, where you simply replace the burnt out one. Instead, they are all linked as a part of a system. Unfortunately for the wallet, this system is only as good as it's weakest link. But that doesn't mean the the remaining sensors are operating properly. Zirconia sensors work by exposing a certain surface area to Oxygen in the exhaust stream. Over 30k mi., this surface area is reduced as carbon and other contaminates condense from the exhaust stream and onto the Zirconia surface, meaning that Oxygen is now denied to that surface area, and the voltage(s) which the sensors produce decline with time as well. It is the value of these voltages which the DME uses in determining the optimal AF metering for the conditions the sensors are telling it are present.

These kind of codes are the ones which require that you put on your detective's hat to figure out what it is exactly which is causing the AF Metering to function improperly. A bad MAF can also throw similar codes as well in addition to throwing a bad MAF code. Hope this helps...

Happy Motoring!... Jim'99

Everyone should listen to Jim on this one...I've been there done that! Once one goes they will all start setting codes and if you replace them one at a time you'll spend more time in the dealership than any of us would like to. Luckily my extended warranty covered them...but only as they expired...so I ended up dropping my car off at the dealership once a week for a month! PITA!! :cheers:

Well, for the record I dont believe anyone disagreed with Jim. We know hes a knowlegable guy.

I've been reading this thread with interest.
I'm at 47,500 mi on my non-S 2001, purchased about 1.5 years ago when it was at about 30 to 35,000. I can say that my car runs as fine as I remembered it at the time, but then again, there might have been a gradual deterioation since then.

My question is how do I know they need replacing? There are no cel lights yet and the car is feeling fine. As per MNBoxster, I should be way over the 30,000 mi sensor life limit.

Also, how good are the discounted ones? The Speedy/PartsTrain guys are selling them at approx $35 each. The OxygenSensors.com guys are at $114 and even then are considerably cheaper than Porsche. Is this case an exception to the rule of you-get-what-you-pay-for?

Having just experienced a Mass Air Flow sensor failure at a bad time, I'm contemplating the replacement of my O2 sensors before they have a chance to fail. (I generally like to choose the place and time of my disasters.)

I'd just go ahead an do it if it weren't for the expense of the OEM sensors. I'll keep an eye on this thread for the next few months. I hope Jim keeps us updated on how well this is working.

Ok, I finally got around to replacing all 4 sensors and I keep getting the following codes (I reset it twice and they come back within 5 miles):

• P0131: Oxygen Sensor Ahead of Catalytic Converter (Cylinders 1 - 3) - Signal Wire Short Circuit to Ground or Incorrect
• P0137: Oxygen Sensor After Catalytic Converter (Cylinders 1 - 3) - Signal Wire Short Circuit to Ground or Incorrect
• P0151: Oxygen Sensor Ahead of Catalytic Converter (Cylinders 4 - 6) - Signal Wire Short Circuit to Ground or Incorrect
• P0157: Oxygen Sensor After Catalytic Converter (Cylinders 4 - 6) - Signal Wire Short Circuit to Ground or Incorrect
• P1115: Oxygen Sensor Heating 1 After Catalytic Converter - Above Upper Limit
• P1119: Oxygen Sensor Heating 2 Ahead of Catalytic Converter - Below Lower Limit

I followed the instructions exactly and all the colors matched up fine. Anyone else have issues?

oh yeah, I used USOS-4000 from Parts Train (the link above) and I have a '99

I know this is going to add insult to injury, but quite often a bad or failing MAF will cause the computer to give O2 sensor fault codes. They have quite a lot to do with one another and play off one another frequently.

If you are sure your sensors are clean (no greasy fingers on the tips before the install) and the wiring is correct, it just might be your MAF. I hope it's not but it just might be.

I currently have no O2 Sensor error code on my boxster right now but i was wondering, IF i were to clean them anyway, Would that improve my performance?

If so, how should i clean them?

The problem with attempting to clean oxygen sensors is that they get a carbon buildup and they're "burned" a little or a lot. There's hardly any way to clean them without scratching the carbon off and then you will damage the sensitive coating on the sensor itself.

I think they're replace only. The MAF is really the same way, but since it's not on the exhaust side it doesn't have carbon buildup and cleaning it can work some times.

I see, thanks randell.

Generic O2 Update
 

It's been about 4K miles now and she still runs beautifully with the generic sensors. Readings are still nice and within range. :dance:

This exact thing happened to me last night. All colors matched and accounted for, and I got most of the same codes (plus a few new ones). The codes and the descriptions are compliments of Durametric... That is one cool toy :)

Stats: USOS 4000 sensors from Speed Auto (Listed on the previous page). This is a 97 Box with the Motronic 5.2.2 DME. All 4 sensors were replaced.

• P0131:Factory Fault Code 10 - Oxygen sensor ahead of catalytic converter (cylinders 1-3)
  Short circuit of wires or limited voltage increase
  
• P0151:Factory Fault Code 18 - Oxygen sensor ahead of catalytic converter (cylinders 4-6)
  Short circuit to ground at signal wire of incorrect voltage
  
• P1119:Factory Fault Code 5 - Oxygen sensor heating 2 ahead of catalytic converter
  Below lower threshold
  
• P0137:Factory Fault Code 12 - Oxygen sensor ahead of catalytic converter (cylinders 1-3)
  Short circuit
  
• P0157:Factory Fault Code 20 - Oxygen sensor behind catalytic converter (cylinders 4-6)
  Short circuit to ground at signal wire or incorrect voltage
  
• P1117:Factory Fault Code 14 - Oxygen sensor heating 1 ahead of catalytic converter
  Below lower threshold
  
• P1121:Factory Fault Code 4 - Oxygen sensor heating 2 ahead of catalytic converter
  Below lower threshold

If anyone else has ran into this, and knows what was done to fix it, please let me know. I'm sending a message to BinaryC to see what his resolution was. I'm going to have just a few minutes tonight to look at it, but as soon as I resolve it, I'll post the answer to this thread.

Thank you guys!

Cheers!

~Aaron

I would check to make sure all of your connections are tight and that no wires have been swapped anywhere. It's usually a really good idea to solder these connections, as the signal output from the sensor is barely 1 volt (at maximum) and any resistance at all will hide the true value. Eve if you're only soldering one wire per sensor, make it the black one.

If you have a multimeter, set it to DC volts. With the engine fully warmed up, disconnect the O2 sensor prior to the first cat (nearest the engine), put one lead on the black wire coming out of the sensor and the other lead to a clean ground on the engine or chassis. With the engine running, you should see voltage vary between around .2 to .8 fairly slowly at idle, maybe 2 or 3 cycles in 10 seconds. Now shut off the engine, but leave the key in the ON position (dash lights all on). Next, check the grey wire coming out of the car harness for continuity to ground (meter set to Ohms). It should have almost no resistance to ground (good continuity). Lastly, verify the two white wires have +12V (meter set to DC Volts) on the car side of the harness.

You didn't get any anti-seize compound on the heads of the sensors, did you? Based on the codes, it sounds as if wires are either swapped (hard to do, I know), loose, or the whole lot of sensors is bad. Were any of the wires faded or damaged in some way on the car harness?

Not all universal 4 wire sensors are the same.

The bank 1 after cat sensor on my 1997 has been replaced 3 times. Every 2 years it gets replaced because every 2 years it is time for a smog inspection. The replacements were the Bosch sensor sold by the dealer with the plug on the end.

This year I decided to go with a Walker made sensor, as I had it with Bosch. Walker makes several universal 4 wires sensors, but not for a 986. The only 986 sensor Walker makes is the "direct fit" which simply means it had the plug on the end.

Yet on ebay there was someone selling a Walker universal sensor for a Boxster for $20, but the seller could not give me the part number so I could look it up in the Walker catalog. Because if you look in the Walker catalog is says that the Boxster universal sensor is N/A. I then emailed Walker and an engineer explained why Walker did not sell a universal for the Boxster, only the direct fit.

So I bought the Walker direct fit on ebay for $109 plus $9 to ship.

I had checked out the Bosch universal sensor - but I had it with Bosch.

I should have the Walker sensor in the mail the next day or so. Will be interesting to see if it works and if it does for how long.

Thanks for the input towards this, guys... I'll hopefully get a chance to look at it this coming thursday or, maybe if I get really, really lucky, this sunday ;)

Schnell - Thanks for the input, and I'll run all the tests and see what I come up with.

Cheers!

Alright, everything seems to check out (on the car/wiring side), my guess is that the cheaper sensors just aren't compatible with the olde schoole (note the extra "e"s, for extra old-timey-ness) DMEs.. Since I really don't have the spare time to be playing around, I'm going to see if I can send back the sensors that didn't work for me. If not, Look for a cheap set of sensors here in the next week or so. I'm going to just buy the Bosch ones from Advance Auto Parts for $80 a piece.

BinaryC Hasn't gotten back to me yet, so I'm guessing that I'm just SOL.

Such is life, eh?

Cheers! :)

hey wonko, did you figure out your 02 problem? i was considering ordering the universal 02 sensors for my car

No, unfortunately I did not... I ended up ordering all four from Advance Auto Parts, getting bosche replacements... it cost $250 or so... I think that it may be an issue with the DME 2.5.5 (the one running the 2.5L engines). I don't have any real way of knowing/checking, though. if you want to try em, I can sell you the set for $100... I still have them sitting in their boxes.