NewBeetle.org Forums banner

1 - 7 of 7 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
Hi,

I'm in the market for a replacement downstream O2 Sensor for my 2002 New Beetle (got the dreaded P0420 code).

I see that pricing for these is all over the map! There are people selling them for $20 and people selling the for $175! The dealership wants $223 for one.

WHY is the pricing so varied? Is there really a difference between the $20 sensor and the $200 sensor?

I need to get this problem fixed soon, because I won't pass an emissions test with this code!

Thanks for your help!
 

·
5/23/10 <3
Joined
·
10,972 Posts
Its probably the brand. Yes, its a bit more pricey, but get a Bosch unit. They are better quality and an OEM parts supplier. GermanAutoParts.com is a great place to buy from.

Also, you should do some troubleshooting. That code can also mean a bad cat.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #3
thanks!

I know the code could mean a bad cat. However, I figured if I could try the O2 sensor first, that would be $20 well spent.

Other than replacing parts and crossing fingers... how do you troubleshoot a "bad cat vs. bad O2 sensor" issue?
 

·
Registered
Joined
·
11,809 Posts
I would look up the correct 02 sensor on Bosch's website. You get what you pay for and crucial parts like the 02 sensor are not something to cheap out on. The 02 sensors are crucial; in having your car run correctly and getting good gas mileage.

https://www.boschautoparts.com/auto

After you get the correct part number; search online for the best price, generally Amazon is the best. Be sure to get the "OE" part listed and one that matches your engine code, that way it is identical to your original one.

Having a scan tool with live data capabilities; can help diagnose these problems and advanced testing with VCDS, can be helpful as well (e.g. Catalyst aging test etc). Check out the link below for testing ideas; some testing can be done without expensive scan tools.

Cat diagnosis:

https://www.google.com/search?q=diagnose+cat+on+volkswagen&rlz=1C9BKJA_enUS603US603&oq=diagnose+cat+on+volkswagen&aqs=chrome..69i57&sourceid=chrome-mobile&espv=1&ie=UTF-8&hl=en-US

http://wiki.ross-tech.com/wiki/index.php/16804/P0420/001056




Sent from AutoGuide.com Free App
 

·
Registered
Joined
·
8 Posts
Discussion Starter #5
Hmmmm.

I already ordered both a upstream and downstream sensor from Amazon. They are both Bosch, but the numbers don't match what I get from that Bosch lookup site. However, Amazon assures me that the ones I ordered will fit my 2002 Beetle 2.0L.

fingers crossed. :)
 

·
Registered
Joined
·
11,809 Posts
I would cancel the order and re-order what Bosch tells you to get. Many times; the wrong part number will have a different plug or length of the harness. They have the "universal" and the "oe"; the "oe" is EXACT fit, vs something made for a number of different cars.
 

·
Registered
Joined
·
3,690 Posts
Bosch numbers are correct. Typically the only variation is Direct Fit, vs.Spliced O2 sensors. Amazon parts listings screw up often for many reasons.

Replacing the O2 sensors will likely make P0420 worse, but O2 sensors are consumable and should be refeshed anyway. Get an OBII smart phone App and you and Log/graph the O2 sensors to find if the cat is bad. Also make sure the engine is running warm enough.
 
1 - 7 of 7 Posts
Top