Enlighten me please

[tjjmon]

Hello,
Long time lurker, first post. I have a 2000 4 Runner that I've owned since 2005. I bought it with 65,000 miles and now it's at 171,000. I've keep up on all maintenance and have never really had a problem except for the P0402 code. It threw this around 70,000 miles. I have basically ignored it as I didn't want to spend the money for new cats. Yesterday I decided to clean the engine. (3.4)
I covered all electrical and the alternator and used very low pressure water to rinse as needed. When the engine was dry I took it for a spin. To my surprise the CEL was off. It came back on after 10 miles or so. The battery was not disconnected for the wash. Any ideas on why the CEL went off for awhile? I am hoping that maybe the CEL is from something other than the cats since it was fairly low miles when the CEL first appeared.

 

[jgue467]

Did you mean p0420 instead? (p0402 is related to an EGR, which the 5vz doesn't have). If so that code does not necessarily mean the truck needs new cats. More likely is it needs the rear 02 sensor instead.

Clear the code and try to determine under what conditions the p0420 is thrown. Mine loves to throw it when I drive slowly offroad every few months, I just clear it and go on. :cowboy:

 

[tjjmon]

oops yes P0420

 

[tjjmon]

Mine is a 2000 with California emissions. I believe the sensor part number is 234-4153. Does that number look correct!

 

[jgue467]

Is that the same part number for a 2000? There are a lot of choices on the Denso link. I have two cats. Does that mean I have the California model?

Don't think that's for your MY (it fits my 01 4wd downstream). There are several listed depending on cali or not, 4wd or not. :cowboy: