Power loss (no codes)

[Aluminum Falcon]

Aloha,
My new to me 2005 Jeep LJ had some power loss issues going up hill and at highway speeds the other day. After reading through the various posts regarding my symptoms I concluded a clogged CAT. I did a temp test on all 3 CATs and the rear had a temp drop that was pretty clear. I removed the CAT and didn't notice anything unusual about. Light shown through, it wasn't broken, and didn't appear to be clogged.

Did I mention I checked my codes and there are none. Test drove the jeep same route that I experienced the issue and I felt it was better but still seemed to lack uphill power. Basically I had to floor it to get it going uphill. And at highway speeds it didn't seem to want to go either.

Another bad CAT? the only thing I have done to the Jeep recently is replace the Transfer case shift mechanism with the Stienjager cable. Could this not being adjusted properly cause some shifting issues in my automatic? I can shift easily to 4 hi but 4 lo still tough to get it in gear.

I need to adjust the cable tension some more to get it to shift to 4 lo properly. Ive ordered new y pipe with CATs from Amazon and new NKT o2 sensors as well. Any thoughts? Am I headed the right direction with replacing the CATs or is the cable shifter for the transfer case potentially my problem? Thanks for the help...trying to figure this out and maybe save some money on expensive parts. Mahalo!

 

[Chris]

The transfer case shifter cable nothing to do with your issue whatsoever.

To me, this sounds like a clogged cat issue, and possibly failing O2 sensors as well. Sometimes they'll throw codes, other times they won't. I will say however that if you continue to drive it, you will most certainly get codes, and I wouldn't be alarmed if they are codes related to the O2 sensors and cats. That being said, I think you're on the right track, as this is what happened to me when my cats failed.

 

[Aluminum Falcon]

The transfer case shifter cable nothing to do with your issue whatsoever.

To me, this sounds like a clogged cat issue, and possibly failing O2 sensors as well. Sometimes they'll throw codes, other times they won't. I will say however that if you continue to drive it, you will most certainly get codes, and I wouldn't be alarmed if they are codes related to the O2 sensors and cats. That being said, I think you're on the right track, as this is what happened to me when my cats failed.

Thank you for the quick reply Chris! I feel you're right the more I go over it in my head. The jeep seems fine at first start up and doesn't get funky until it's good and hot. Again thank you!

 

[Chris]

Thank you for the quick reply Chris! I feel you're right the more I go over it in my head. The jeep seems fine at first start up and doesn't get funky until it's good and hot. Again thank you!

You're welcome! Like I said, I'm almost certain you're on the right track. I'm betting once you install new cats and O2 sensors your issue is going to go away.

 

[ItchyDong]

Did you ever find a solution?

 

[Jerry Bransford]

Has your mpg taken a big hit since the power loss started? If so you might just have a bad upstream O2 sensor. A bad O2 sensor does not usually set a trouble code in the computer.

 

[13jeeps]

I don't disagree but how did you diagnose clogged cat or cat issue?

 

[Aluminum Falcon]

Thanks all for the help. Ive replaced the cat with a magna flow and all the O2 sensors with the ntk ones. Runs so much better now.