Engine Code P0421 2006 Jeep Wrangler

[bwimsett]

I have this code (P0421) come on this afternoon on my 2006 Jeep Wrangler with 116000 miles on it. I was going to replace the 02 sensors first before I replace the cats. The code seems to be directed toward the cats or the 02 sensors. Has anyone had this engine code before? Any ideas? It just got colder in Texas high 40s and low 50s could it be the weather?

Thanks.

 

[macleanflood]

Get a code reader that can read live data.

Monitor the O2s. If they consistently go over .9v they're bad.

Lot of perfectly good O2s get tossed diagnosing things.

Welcome to the forum!

-Mac

 

[LONGJP2]

I have this code (P0421) come on this afternoon on my 2006 Jeep Wrangler with 116000 miles on it. I was going to replace the 02 sensors first before I replace the cats. The code seems to be directed toward the cats or the 02 sensors. Has anyone had this engine code before? Any ideas? It just got colder in Texas high 40s and low 50s could it be the weather?

Thanks.

Mine throws that quite often, usually during long idles.
Tightening the pre-cat bolts seems to help (for a while).
However, I'm probably due for new cats as well.

 

[bwimsett]

Get a code reader that can read live data.

Monitor the O2s. If they consistently go over .9v they're bad.

Lot of perfectly good O2s get tossed diagnosing things.

Welcome to the forum!

-Mac

Thank you I'll try that.

 

[bwimsett]

Mine throws that quite often, usually during long idles.
Tightening the pre-cat bolts seems to help (for a while).
However, I'm probably due for new cats as well.

Thanks for the idea.