Bank 2 cat problem: O2 position 1 reading lean and cat twice as hot as bank 1

[06RC]

2006 TJ

Cleaned all injector and new orings and throttle body gasket and checked iac and map sensors all good new plugs new coil over bank 2 cat scoped it and looks bad and seems to be getting to much back pressure and plugs on 5 & 6 show lean but 4 looks good any ideas on what could be the problem? Maybe skid cat clogged

 

[Chris]

Sounds like you might be dealing with some clogged cats potentially.

When was the last time all the O2 sensors were replaced?

 

[06RC]

Sounds like you might be dealing with some clogged cats potentially.

When was the last time all the O2 sensors were replaced?

Just replace both on bank 2 and it's not throwing any codes but on my scanner it shows bank 2 1 running lean the jeep has 160000 on it

 

[Chris]

Just replace both on bank 2 and it's not throwing any codes but on my scanner it shows bank 2 1 running lean the jeep has 160000 on it

I'm betting it's a clogged cat. I'd probably check your fuel pressure just to be sure it's within spec too. If it's running too lean that could exacerbate the lean condition leading to issues like this.

Still, given how many times I hear about issues like this and it ending up being clogged cats, that's what my money is on.

 

[06RC]

I'm betting it's a clogged cat. I'd probably check your fuel pressure just to be sure it's within spec too. If it's running too lean that could exacerbate the lean condition leading to issues like this.

Still, given how many times I hear about issues like this and it ending up being clogged cats, that's what my money is on.

Yep checked fuel pressure and it is good 58 psi at idle holds steady and it i can take both post cat 02 out and leave plug in and it will idle almost as it should so I'm sure something is clogged up causing to much back pressure and maybe that's causing the lean condition on bank 2 cat because it gets up to about 600 degrees on it and front cat around 200

 

[Chris]

Yep checked fuel pressure and it is good 58 psi at idle holds steady and it i can take both post cat 02 out and leave plug in and it will idle almost as it should so I'm sure something is clogged up causing to much back pressure and maybe that's causing the lean condition on bank 2 cat because it gets up to about 600 degrees on it and front cat around 200

Yep, I think we’re both tracking. My bet is on clogged cars as well.

 

[AndyG]

Clogged cat. The typical lifespan is somewhere between 80 and 120,000 miles for catalytic converters..

When I was little, I had a cat named Woem. That is meow spelled backwards.

 

[06RC]

Yep, I think we’re both tracking. My bet is on clogged cars as well.

Any suggestions on good replacement and do away with cats and not have check engine light on

 

[GoldenGorilla]

My first thought is that the upstream O2 sensor was not tightened to the manifold enough to seal, leaking air in. However this should drive it to run richer.

Possible the injector seals on 5 and 6 are leaking air. Test by spraying some brake fluid or intake cleaner around the injector ports on the manifold and see if you've got a leak.

Otherwise, trouble in catville

 

[GoldenGorilla]

Any suggestions on good replacement and do away with cats and not have check engine light on

The eastern ones are among the cheapest options that seem to hold up.

 

[06RC]

My first thought is that the upstream O2 sensor was not tightened to the manifold enough to seal, leaking air in. However this should drive it to run richer.

Possible the injector seals on 5 and 6 are leaking air. Test by spraying some brake fluid or intake cleaner around the injector ports on the manifold and see if you've got a leak.

Otherwise, trouble in catville

Yeah done all that and replaced all the orings on injectors and switched around lol still same
Thanks

 

[Chris]

Any suggestions on good replacement and do away with cats and not have check engine light on

Walker is a good brand for replacement cats.

 

[06RC]

My first thought is that the upstream O2 sensor was not tightened to the manifold enough to seal, leaking air in. However this should drive it to run richer.

Possible the injector seals on 5 and 6 are leaking air. Test by spraying some brake fluid or intake cleaner around the injector ports on the manifold and see if you've got a leak.

Otherwise, trouble in catville

Ok finally found the culprit between cylinder 5 # 6 the exhaust manifold has a crack and sucking air.
So what is a good replacement for the manifold 2pc ? 1 pc ? I have already gutted the cats and ? Do hp tuner or what ?

 

[06RC]

Yep, I think we’re both tracking. My bet is on clogged cars as well.

Well found the problem there is a small Crack in the exhaust manifold between cylinder 5 & 6 and sucking in air.
I gutted bank 1 & 2 cats so I'm assuming the check engine light will stay on now.
Should I just keep stock pipes and get tuner to disable 02 sensor?

 

[Chris]

Well found the problem there is a small Crack in the exhaust manifold between cylinder 5 & 6 and sucking in air.
I gutted bank 1 & 2 cats so I'm assuming the check engine light will stay on now.
Should I just keep stock pipes and get tuner to disable 02 sensor?

Yeah if you’re going to run it this way you will want new pipes and a tuner to disable the post-cat O2 sensors.

 

[06RC]

Yeah if you’re going to run it this way you will want new pipes and a tuner to disable the post-cat O2 sensors.

What tuner be best hp?

 

[Chris]

What tuner be best hp?

HPTuners

 

[06RC]

HPTuners

I'm going to replace exhaust manifold with the skp from rock auto unless u have better suggestions and can I still drive it with stock gutted cats u til I can afford a new pipe and a tuner ?

 

[macleanflood]

I'm running the Banks headers on my 97. I probably would have gone with cheapie Amazon or eBay ones just so I could cut off the donut seal and weld on a v-band.

If you live somewhere that doesn't inspect emissions consider simplifying exhaust to the earlier TJ style. Manifold to single downpipe to a cat next to the transfer case. You can move your existing O2s to make the PCM happy.

-Mac

 

[06RC]

I'm running the Banks headers on my 97. I probably would have gone with cheapie Amazon or eBay ones just so I could cut off the donut seal and weld on a v-band.

If you live somewhere that doesn't inspect emissions consider simplifying exhaust to the earlier TJ style. Manifold to single downpipe to a cat next to the transfer case. You can move your existing O2s to make the PCM happy.

-Mac

I thought about banks but have read so much about them cracking also.
So thought just doing the skp at 75.00 each