P0430 and O2 Sensor reads

[Mikeyman]

Hi gang,

Looking for some experienced members to have a look at my O2 sensor readouts and help me solve P0430.

Recently replaced cracked bank 2 exhaust manifold, trying to determine if I have O2 sensor issues or leaks. I've attached the fuel trims and O2 sensor traces - please let me know if any other info is helpful. If it's cats, so be it... but don't wanna throw parts at this if I don't have to!

 

[BigAL07]

First check for leaks at the manifold and bank 2 cat. I’ve read that if sensors upstream and downstream mimic each other it could be a faulty down stream sensor. This was particular to the 3.8. Not sure on the 3.6. Lots of issues on this code. Vacuum leaks, egr, plugs , wires ect. My 07 has the same NTK sensors downstream on bank 1 and bank 2. Easy to swap out and see if it follows. Good luck

 

[BLACKJKU]

lots of info here have you read any of it?

jeep wrangler P0430 - Google Search

 

[Mikeyman]

lots of info here have you read any of it?

http://[URL]https://www.google.com/...CCBAAGIAEGLEDwgIFEC4YgAQ&sclient=gws-wiz#ip=1

[/URL]

BLACKJKU,

You may have noticed this was my first post. Rest assured that having gone through the trouble of making an account and asking for help is because I was not able to solve my problem by searching Google.

It sounds by your reply that you actually know something that I don't. Since you're a moderator, staff member, and supporting member, I'll assume you've got tons of experience and knowledge. I'm an aerospace engineer and I would love to have a technical discussion with you over what I've read and ask some of the questions I have based on my own research. I'm probably not understanding or misinterpreting something I've read.

If you have something you'd like to share to help me interpret the vast amount of information on this code that is specific to my case, please, let's walk down this path together. Replying "did you try googling it" doesn't help me, or anyone else in the community.

 

[BLACKJKU]

BLACKJKU,

You may have noticed this was my first post. Rest assured that having gone through the trouble of making an account and asking for help is because I was not able to solve my problem by searching Google.

It sounds by your reply that you actually know something that I don't. Since you're a moderator, staff member, and supporting member, I'll assume you've got tons of experience and knowledge. I'm an aerospace engineer and I would love to have a technical discussion with you over what I've read and ask some of the questions I have based on my own research. I'm probably not understanding or misinterpreting something I've read.

If you have something you'd like to share to help me interpret the vast amount of information on this code that is specific to my case, please, let's walk down this path together. Replying "did you try googling it" doesn't help me, or anyone else in the community.

You said that you recently repaired a exhaust leak and after repairing sometimes you have to do a ECM reset. Did you do that?

Also when I Googled to see some of the fixes it was saying to do a Cat cleaning which could help.

NGK O2's aren't real expensive so you could try replacing the O2 sensor.

Alot of Members won't search or don't know how to so they just Post, you didn't say what you did other than Scan for issues.

I was just trying to get more info for myself and the others who might want to help you.

 

[Mikeyman]

First check for leaks at the manifold and bank 2 cat. I’ve read that if sensors upstream and downstream mimic each other it could be a faulty down stream sensor. This was particular to the 3.8. Not sure on the 3.6. Lots of issues on this code. Vacuum leaks, egr, plugs , wires ect. My 07 has the same NTK sensors downstream on bank 1 and bank 2. Easy to swap out and see if it follows.

You said that you recently repaired a exhaust leak and after repairing sometimes you have to do a ECM reset. Did you do that?

Also when I Googled to see some of the fixes it was saying to do a Cat cleaning which could help.

NGK O2's aren't real expensive so you could try replacing the O2 sensor.

Alot of Members won't search or don't know how to so they just Post, you didn't say what you did other than Scan for issues.

I was just trying to get more info for myself and the others who might want to help you.

Thanks for that reply.

I didn't know about the ECM reset - I'll give that a go.

I was trying to use the fuel trims and voltage traces to determine whether or not the CATs were plugged or damaged. Based on what I've read, bad or plugged CATs are indicated by upstream and downstream O2 sensors showing similar behaviour (both switching at similar rates). The data I retrieved with the scan isn't clear cut to me. Bank 2 does have some switching but I'm not sure if it's indicative of a CAT issue, as it isn't as frequent as some of the examples I've seen. I'm also a little interested in the LTFT numbers, as they seem a little high.

All that together, with the research I've done, here's where my head is at:
-Tired upstream O2 sensors causing fuel trims that overwhelm the CATs, resulting in the efficiency to fall below threshold;
-Vacuum leak (but not convinced since bank 2 is affected differently than bank 1);
-Another exhaust leak; or
-Actual failed CATs.

I'll start with the ECM reset and see how that goes. Next I'll take BigAL's suggestion and swap the down stream O2 sensor and see if the fault follows. With almost 190 000 km, I'm thinking it might just be time for new O2 sensors anyway, so that's on the table as well.