Cant shake this p0420 code!!

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Jun 7, 2023 | 04:33 PM

Eurynomestolas

Thread Starter

Senior Member

Joined: Oct 2019

Posts: 150

Cant shake this p0420 code!!

This code is driving me insane. I replaced the cat and o2 sensor and this code comes back! any ideas? Can it be the second one? i am thinking of cutting it out an straight piping it!

Jun 7, 2023 | 10:44 PM

bronxteck

Senior Member

Joined: Apr 2019

Posts: 3,192

From: BX NY North East

maybe you can "test" with a long reach spark plug non fouler on the last oxygen sensor?

Jun 8, 2023 | 06:55 AM

Disel

Senior Member

Joined: Jan 2023

Posts: 133

Quote:

Originally Posted by Eurynomestolas

This code is driving me insane. I replaced the cat and o2 sensor and this code comes back! any ideas? Can it be the second one? i am thinking of cutting it out an straight piping it!

Maybe the second oxygen sensor is buggy (behind the catalyst). It's easier to fake it then. That's what I did when I got sick of the error. Then I changed to another collector.

Jun 8, 2023 | 08:51 AM

Eurynomestolas

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Senior Member

Joined: Oct 2019

Posts: 150

Quote:

Originally Posted by bronxteck

maybe you can "test" with a long reach spark plug non fouler on the last oxygen sensor?

how do you do that? Just put a spark plug into where the downstream o2 sensors goes? I am sick of this code if i just have to get a fouler I dont care.