P0420 + Red Triangle Disappeared after 30 min

From what I've researched, P0420 is just the O2 sensors in the Cat. P3190 is loss of engine power. It might have just been a malfunction and you needed to restart your car.

 

That happened on my gen 2 several years ago when I went down a hill. Could be the gas tank or a loose HV battery connection. I'm not an expert, but @Patrick Wong is so maybe he'll help.

 

Wondering? You should know if it is.

 

1. Check the engine oil level, do not guess.
2. Clean the throttle body interior now.
3. When were the iridium spark plugs last replaced? If you have no knowledge that was done, do that now.
4. Work on saving sufficient funds to replace the catalytic converter if you expect to renew your auto registration in CA.

 

It is WELL known that Toyota and Subaru log P0420 codes for even the slightest loss of catalytic converter efficiency, WELL before this loss can even be detected by a typical emissions analyzer. There are any number of causes for the P0420 DTC, only one of which is actually a failed or failing "cat".

Common things that can cause P0420 are:
- oil burning (wear, bad pcv valve, overfull of oil, etc)
- exhaust leak
- lazy O2 sensor (rear)
- worn out WBO2 sensor (AFR sensor, front)
- poor air/fuel metering
- tune up
- defective sensors (other than O2/WB O2)

 

My red triangle goes on when my 06 is low on oil.

 

Old thread (I know) but if you wait that long to top up your oil, you're damaging your car. Likely an oil burner. Expect catalytic converter problems.

 

It has been burning oil like this for a long time, maybe 2 years? And then the cat converter got stolen, and replaced TWICE. But maybe that is the reason I have the p0420 on now? Because the second cat converter didn't trip the check engine light until I hit a big puddle on a highway.

I mean I have to top off the oil fairly often.

 

Hi I just replaced my hybrid battery and got the same p0420 code how can I check for HV battery connection problem is there a diagram/ video?

 

P0420 is a code set by the ECM indicating that the catalytic converter efficiency is below acceptable limits. It has nothing to do with the hybrid drive system.

Use the search feature to check the Gen 2 forums for P0420. I have made a number of posts about what to check before condemning the cat.

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