P0420 Code issue

AmunRoo Aurora Owner Posts: 559	P0420 Code issue Dec 14, 2019 19:04:40 GMT -6 AUROD X likes this Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by AmunRoo on Dec 14, 2019 19:04:40 GMT -6 Got a P0420 code. Changed the CAT and the code still came back. could it be the secondary O2? It is a Flowmaster high flow cat. would spark plug non fouler fix this code? need to pass emissions in IL lol

Paulaurora Super Moderator Posts: 3,828 Staff Member	P0420 Code issue Dec 14, 2019 21:28:11 GMT -6 Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by Paulaurora on Dec 14, 2019 21:28:11 GMT -6 99% its the cat.
	Own:2003 Aurora 4.0 3rd Owner! All options 145k Had: 1998GX 168,000 Intrigue-RIP total loss. 1999 Intrigue GLS 215,000 mil-Trade it in for Aurora 2001 Aurora 4.0 2nd owner! miles 22,000~170,700- Sold 2018 Volvo s90 Inscription. Paul.

AmunRoo Aurora Owner Posts: 559	P0420 Code issue Dec 15, 2019 0:33:57 GMT -6 via mobile Quote Select Post Deselect Post Link to Post Member Give Gift Back to Top Post by AmunRoo on Dec 15, 2019 0:33:57 GMT -6 I just changed it...