2002 Passat 1.8T (B5.5) AWM FWD bad O2 sensor

[mikefl]

My check engine light is on and I had been ignoring it for quite a while. I have 121K on the car.

The diagnosis at AZ yesterday showed code P00030.

Bank 1 Sensor 1.

From my research that would be the upstream sensor.

• Can someone tell me the location of this sensor on the AWM 1.8T 4-Cyl engine?

Searching the forum I get a lot of info on replacing the O2 sensors on V6 engines but not much on AWM 1.8T.

• Also I couldn't find any DIY for the AWM engine. If someone has a link to it please let me know.

Thanks guys for all your help.

[VAGguy]

If it's the upstream sensor....

1. Open your hood and move over to the passenger side
2. Find catalytic convertor
3. Sensor is mounted just before the cat.


No DIY needed. Get a normal or lambda wrench that fits and remove. Installation reverse of removal.

[mikefl]

If it's the upstream sensor....

1. Open your hood and move over to the passenger side
2. Find catalytic convertor
3. Sensor is mounted just before the cat.


No DIY needed. Get a normal or lambda wrench that fits and remove. Installation reverse of removal.

The one circled in green below is the upstream O2 sensor, right?



* What is the best place to buy it? NAPA says $180. Stealership $215.
OEM Part No. 1K0998262d.
Is it OK to put any generic ones?

* Can I remove it without a lambda wrench(Is there some modified tool that can be constructed?) Or do I need to absolutely buy the lambda wrench?

[VAGguy]

That's the one. You could try a regular wrench but space is limited. Try to get a sensor that is not universal. Look at Ecs, german autoparts....importrp.etc

[Harold]

Hi Mike,

Funny you should post about this. Just finished the exact thing on my AWM less than 2 hours ago. Our car is 700 miles shy of 120k. There is a pretty good description in the information Index for a 1.8T

Simple pre-cat oxygen sensor how-to, A.K.A. heated 02 sensor

I got mine on Ebay item 290331402165 from Europarts Direct for $70 including shipping. Took about 1 week to receive it. For me it was my pre-heater circuit that failed so I could still drive the car and I wasn't in a real hurry to replace it. Otherwise you probably should be able to find one in a local autoparts place It's just a plain Bosch model 17090.

I would spend the money ($10) on a good crow feet wrench size 7/8" designed for an O2 sensor from a car place. I wouldn't get a socket with a slit because the angle of the sensor is towards the airbox and you would have little space for a wrench. I tried some of my other wrenches but none of them seemed to fit real well. For $10, I did not want to go through the trouble of removing the airbox. Plus with a wrench, you don't really know how tight you are installing it. Bentley says 50 Nm (37 lbsft). Might as well do it right.

The easiest is to undo the 3 screws from the coolant reservoir and disconnect the plug underneath. That will give you better access to the sensor plug on the firewall (second from the left) plus that will also give you space for your arm to reach around and undo the ties.

Removing the sensor and unplugging it took less than 5 minutes. Then it took another 30 to deal with the 4 straps to undo/cut them an replace them. The 3rd one (counting from the sensor) is especially tricky unless you want to cut it. I did not cut my old sensor just in case I had a surprise with the new one.

After a TB job, you could do this one with one hand tied behind you back. Plus at the dealer you would have probably paid about $350 between the sensor, labor, and checking and clearing the code. So you will be saving at least $250 in 1/2 hour.

[VT Variant]

Advance Auto rented me the crow foot wrench for free when I did mine. I got my sensor from ECS Tuning and I think it was around $90.

[mikefl]

Hi Harold,

Thanks a bunch for some truly useful advice and links.
Keeping my fingers crossed that the new O2 sensor also fixes the slight jerk I get soon after the TIP shifts from 2nd to 3rd gear when driving at low RPMs. Then my Passat will be as good as new!!!

VT Variant, thanks I will rent the crowfoot wrench since its free at AAP. I have to head there anyway to get some engine degreaser.

Mike.

[meresda]

Just got a Bosch 17090 from Amazon for $70. I've always had good luck with Bosch sensors.

[mikefl]

Hi Guys,

I received Bosch 17090 from Amazon yesterday, I purchased it for $70.

The O2 sensor is black on one end instead of copper color.
Does that mean it is a used part?
I have the pictures below.

[mikefl]

Just got a Bosch 17090 from Amazon for $70. I've always had good luck with Bosch sensors.

Was it sealed?

[mikefl]

Ok I removed the old O2 sensor and put the new one in. I used the rental kit from AAP and used generous amount of WD40 to loosen the sensor. I tightened the new sensor to 37 ft-lbs.
However when I started the car there is white smoke coming from around the sensor area. Is this the WD40 burning due to the heat of the CAT?

[mikefl]

The white smoke must have been the Wd40 burning. It started after the engine became hot and kept on even after engine was turned off.

So I kept the car running while I cleaned it from inside.

Then I went for a ride with the family. It drives great. Checked the CAT area after the drive, no smoke.

I was hoping the new O2 sensor would solve the slight jerk I felt after crossing 20 mph at low RPM but that issue still occurs.

[mikefl]

Thank you Harold and all others for your help.

I did remove the airbox, it added 15 minutes to my task (incl putting it back on) but made it very easy to remove the sensor.

I made a rookie mistake when removing the old sensor though, instead of turning the wrench counter-clockwise to loosen it, I was turning it clockwise. It moved a little (tightened) and then wouldn't budge. I applied so much pressure, the O2 socket damaged the sensor. And I kept wondering why was it so tight.

After 1/2 hr of this fight, I took a break and them realized my mistake. I turned it counter-clockwise and sensor came off easily.

One more thing accomplished!!!

[BSK]

MikeFL: The sensor in the picture is a USED SENSOR

[mikefl]

MikeFL: The sensor in the picture is a USED SENSOR

Can you please clarify how to tell a used sensor apart from a new one?

Nothing on the Amazon link states its used but the box it came in was not sealed.

http://www.amazon.com/Bosch-17090-Ox...3097384&sr=8-1

[BSK]

Look at the HEAT marks on the sensor. a new sensor does not have any heat markings on it and comes in a sealed bag as well.

take a look at my writeup on audiworld that shows a new and old sensor next to each other:
http://www.audiworld.com/tech/eng114.shtml

[mikefl]

It is a great writeup.
Sorry for the dumb question, when you say HEAT markings, can you point out in the image where exactly?
Damn it, I have already put it in and I don't want to now go through the whole shebang of returning the part. At this point, I will only do that if its defective.

It was not sealed, that should have been my first clue.

[BSK]

look at the discoloration from the top starting at the Bosch logo going down the numbers

[BSK]

NEW

Old vs New


I could be wrong but im pretty sure that your "new" sensor is not as new as we want it to be.

Either way; if it works then roll with it.

[mikefl]

This is the risk of buying things from Amazon. Harold, Meresda, were your O2 sensors sealed?

[Harold]

Hi Mike,

Glad it seems like it worked out for you. Did the MIL finally go away? From your picture, the sensor looks a lot more like the old one I removed than the new one I installed. I still kept the old one so I can take a picture if you want. My new one was polished silver color without any brown deposits.

Mine came in a Bosch cardboard box but was not sealed in plastic. It definitely looked like a brand new sensor to me when I took it out of the box.

Probably not much you could have done at this point, especially now it is installed. Not right for Amazon to sell a used sensor for a new price. May have been a customer return.

Hope it works good, Harold

[mikefl]

Thanks Harold. Yes the MIL finally went away today, I was happy to see it go off. I finally drove the car today WOT without worrying about frying the CAT.

The sensor itself looks used but the 6-pin connector was looking like new. As you said it might have been a return.