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

[xclusivecar]

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!!

[ohioboxster]

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

[socratic]

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?

[KevinH1990]

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.

[binaryc]

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?

[binaryc]

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

[RandallNeighbour]

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.

[Wonko The Sane]

Originally Posted by binaryc

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?

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

[Rodger]

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?