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Discussion Starter · #1 ·
I was reading on here that this is an O2 Sensor or Catalytic Converter problem.

I have an oil leak and when searching for it found that my right front inner CV boot is ripped.

Now the check engine light comes on and I read 0420 with my Creader LAUNCH Tech USA Products

Could not the problem be oil leaking onto the O2 sensor or fouling the catalytic converter?
 

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P0420 is a not an O2 sensor problem typically. It is a fault code for the catalytic converter efficiency. These can be nuisance codes, sometimes caused by an engine that runs too cool and the exhaust and converter carboned up. It can also be caused by a failing converter, which VW did have a lot of problems with.

It is not something I could jump all over, it will not leave you stranded, jut annoying.
 

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Discussion Starter · #4 ·
Oil Leak

It must be something to do with the oil leak. Probably just leaked on the wiring. Discount Catalytic Converters says, "PO420 & PO430 Codes
Fix The Real Problem First, Then Change The Converter

The last thing you do when you get a "Below Efficiency or Under Threshold"
code is to immediately change the Catalytic Converter !!!

After reading the DTC trouble codes here is what to check for:

Rich Running Condition

Bad or Lazy (80,000 + Miles) Upstream O2 Sensor

Leaking Injectors

Bad Temperature Sensors

Bad Mass Air Flow Sensor

Miss Fire (Coil Packs)

Bad or Old Spark Plugs

Clogged Air Filter"

How could the oil that's dripping on the driveway have anything to do with the above?


P0420 is a not an O2 sensor problem typically. It is a fault code for the catalytic converter efficiency. These can be nuisance codes, sometimes caused by an engine that runs too cool and the exhaust and converter carboned up. It can also be caused by a failing converter, which VW did have a lot of problems with.

It is not something I could jump all over, it will not leave you stranded, jut annoying.
 

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Oil dripping on the O2 sensor could possibly have an impact on the P0420 code, but I doubt it.

O2 sensors have to reference air outside of the exhaust system to function problem.

BUT I doubt the oil leak has anything to do with the P0420 code as I stated.

The 2.0l converters are known for problems where the insulation around the cell fails and there is a massive amount of exhaust is leaking around the catalyst.

First thing I would do is verify the engine operating temperate while at idle and cruising on the highway.

Then if you had OBDFusion you could Log the O2 sensors and see how bad the converter is operating. You could also have exhaust leak that is letting fresh air to get into the exhaust stream and generate a error that in general would be false.
 

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Discussion Starter · #6 ·
Engine Temperature

I have a glow shift temperature gauge and one by Sunpro. I'll install one of those tomorrow.
 

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Discussion Starter · #8 ·
OBD Fusion

I went to McDonalds to get the OBD Fusion from the App Store installed on my iPad. They wanted $10 so I treated myself since it's that time of year :) It looks like I need some sort of connection to the car though. Would this be okay? ELM327 WIFI Wireless ELM327 OBD2 OBDII Auto Diagnostic Scanner Tool Adapter for Smartphone / PC / iOS / iPhone/ iPad/ iTouch /Mac

http://www.amazon.com/gp/product/B00QRE0OOA?keywords=elm 327&qid=1449966496&ref_=sr_1_5&sr=8-5
 

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First thing I would do is verify the engine operating temperate while at idle and cruising on the highway.
What temp would expect to see? I have the same P0420 code and my BEV engine is running 198-199 down the highway with ambient air temp of 20 F. It is at ~194 at idle.
 

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Here we go again..

I had the same problem a few years back, P0420 at random. IMO it's a carboned up exhaust system. I fixed mine up for $8 and that code has never come back. good luck to ya.
 

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What temp would expect to see? I have the same P0420 code and my BEV engine is running 198-199 down the highway with ambient air temp of 20 F. It is at ~194 at idle.
Sounds a bit low, but not as bad as I have seen these engine run.

205F is the typical temp at idle, 194 seems low for idle.

Thermostat is only $10 or so, just a PITA to replace in the Winter.
 

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Discussion Starter · #13 · (Edited)
Never Fixed It

I had taken the battery out and charged it for a few days then today I decided to throw it in and take Marilyn for a spin. The check engine light never came back on. I checked the charging by putting a volt meter across the battery terminals at idle and it was at 14V which is good.

I still haven't figured out how to use the Veepeak Torque scanner. The instructions suggest going to Torque OBD2 Wiki for detailed App settings and functions from the software publisher.

On that site it says, most ELM Wi-Fi scan tools use IP address 192.168.0.10
Set IP address of iOS device to a different value by adding 1 to the last # of the ip address of scan tool. 192.168.0.11.
Set the subnet mask 255.255.255.0
7. Open OBD Fusion and select Settings>Preferences>Communications.
8. Under Communication Type, select Wi-Fi.
9. Under the Wi-Fi Settings category, select your OBD scan tool. If you do not see your scan tool listed, select Custom.
10. If you selected Custom in the previous step, you must set the IP address and Port number of your Wi-Fi scan tool. Refer to the documentation for your Wi- Fi scan tool to determine the IP address and Port number. Most ELM Wi-Fi scan tool use the IP address 192.168.0.10 and Port 35000.
11. Tap the back button to return to OBD Fusion Home Page.
12. Tap connect button to connect to the vehicle.

How do I find out what the IP address is the ELM Wi-Fi scan tool is using? I didn't see anything in the documentation that came with it.
 

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Discussion Starter · #14 · (Edited)
Code 420 Again!

Drove Marilyn to the Next City and on the way back home the check engine light came on. I parked it in the street, removed the ELM 327 Adapter and plugged back in my Creader to get the same 420 code. What a nuisance!

I'll check the PCV valve tomorrow.

Wish I could configure the Veepeak Torque scanner! :confused:

Ended up going to Autozone where the man thought I should replace the O2 sensor. I said I'd like to clean it first.

Haynes says, "A plugged breather, valve or hose will cause excessive crankcase pressures resulting in oil leaks and sludge build-up in the crankcase. Check the components for restrictions and clean or replace the components as necessary. Be sure to check the basic mechanical condition of the engine before condemning the crankcase ventilation system (see chapter 2C)."
 

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Do not replace the O2 sensor(s) yet, this will not likely solve anything. Doubt SeaFoam will help much. But you also need to verify the engine temperature before you start to replace any parts.

As for OBDFusion, you should not need to know the IP address or anything like that.

The FIRST think you must do before you even open the OBDFusion App is connect the phone to the interface. Use the Airport icon to find and connect to the adapter which needs to be plugged in and the engine is best to be running.

Once the phone is connected the the interface, then you can launch the OBDFusion App.
 

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Discussion Starter · #17 ·
Got It!

I sat there until I figured it out.

Saw the stored code 0420 then got rid of it by clearing it with OBD Fusion as it said the car was not ready for emissions testing. Hopefully it will never come back.

The dip stick tube is fixed and no more oil should be getting in the catalytic converter. :)
 

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Discussion Starter · #19 ·
Marilyn Went Over The Hill Again - Same Code

While driving through the San Fernando Valley the check engine light came on again. I stopped at McDonalds to take a break with a coupon for a buy one, get one Quarter Pounder then drove the rest of the way home.

Plugged in my new Veepeak OBD2 wifi device then used OBD Fusion on my iPad to reveal the same code 0420 again.
 

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Time to get Freeze Frame data, this is important.

Once you clear the codes/SES/CEL/MIL light, the Freeze Frame info will be erased until the next time the SES/CEL/MIL lights up. This will also indicate what the engine coolant temperature is operating at.

Learn how to Log and then we can look at the converter behavior and efficiency.
 
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