|09-18-2012 07:23 AM|
|TnDz TJ||Makes sense... I was thinkin along that line... just considering a flow factor. I am wondering if the the only difference in flow rate is the ID of the inlet and outlet. If that is the case, there would be no harm in getting the 2" OD and working from there.|
|09-18-2012 01:31 AM|
After writing this, I'm now remember thinking the 2" O.D. might have been a better choice because of how large the outlet was after trimming the cat. I think there would have been a little less work tapering the trimmed cat down to the 2.25" O.D. head pipe, because the trimmed outlet size would have been smaller and closer to the head pipe diameter.
|09-17-2012 11:41 PM|
Thanks... the only concern that comes up is flow... is there a difference? HMMMMM....
|09-17-2012 10:47 PM|
|BarryDaviso||That just seems too easy.|
|09-17-2012 10:39 PM|
I bought a 2 1/4" O.D., but yeah, you end up cutting the pipe off anyway. I'd just buy the one that cost less if there was a price difference.
|09-17-2012 10:26 PM|
Do you recall the actual OD of the the exhaust tube? I havent measured mine yet, wondering if it really matters from 2-2.5" due to cutting and reducing inward. thanks!
|09-17-2012 10:23 PM|
|09-17-2012 10:21 PM|
|09-17-2012 10:19 PM|
Unfortunately, I didn't become aware of using stainless filler until afterwards. I'll check it next spring and see how it's doing. Thanks for the tip!
|09-17-2012 04:36 PM|
X2 on the Rock Auto... cheapest I have found at $300 or so..... but for $100, I will be doing this cat swap within the next month or two.
|09-17-2012 10:52 AM|
Ingenious solution, but I gotta ask, did you weld it up with stainless filler ?
I hope so, because at the temps those cats run mild steel will rust out pretty fast and you'll get to do it again.
|09-17-2012 10:32 AM|
|09-17-2012 09:42 AM|
|Mark b||Awesome! That is really cool. There is no aftermarket downpipe with cats for the TJ's correct?|
|09-17-2012 08:57 AM|
|hammmike||I still need two more.|
|09-17-2012 08:56 AM|
|hammmike||I need to get in 15 posts so I can post in the classified ads|
|09-17-2012 08:55 AM|
|09-17-2012 08:55 AM|
|hammmike||That is a really neat fix. I had a set replaced on my jeep and paid way to much to have it done. I never even considered something like this.|
|09-01-2012 09:55 PM|
|09-01-2012 09:40 PM|
|09-01-2012 08:19 PM|
|09-01-2012 06:07 PM|
|tpeerson||Oooh, it would be an honor to be sticky!|
|09-01-2012 05:31 PM|
|Tdog02||That just seems too easy. Nice write up, should be a sticky so I can find it when I have to do mine.|
|09-01-2012 05:20 PM|
|tpeerson||Great! Please post your progress.|
|09-01-2012 04:37 PM|
|TnDz TJ||NICE!!! Thanks again for the info... gonna head this up and replace both while I'm at it.... can't hurt and only for $100.... shoot... can't pass this up.|
|09-01-2012 04:27 PM|
TnDz TJ- I did this back in April, a little over 4 months ago... never saw the code again.
Jerry- It really wasn't a big deal dropping the head pipe, and you can't beat the $aving$.
|09-01-2012 02:28 PM|
|Jerry Bransford||That was awesome, please come to San Diego and do the same thing to mine. I could weld the new cat into place but I'm too old and lazy to want to have to pull all that off the engine.|
|09-01-2012 02:06 PM|
You are my hero!!! I was hoping and praying someone would try this out. Give a shout back in about 2 weeks of driving and let us know if the CEL and code comes back.
Thanks for the kitty link too!!!
|09-01-2012 01:41 PM|
$49.95 head pipe catalytic converter replacement on 2001 4.0 - Fixed my P0432 code
My 2001 4.0L TJ was throwing out the P0432 code- Catalyst System Low Efficiency Bank 2. Thanks to the incredibly wicked awesome $4.95 Torque Pro OBDII Android app and a wireless bluetooth OBDII code scanner, I discovered that the pre and post O2 sensors were returning basically identical voltages, indicating that the catalytic converter had no effect on the exhaust passing through it.
Since both O2 sensors passed testing, I was confident the problem had to be the catalytic converter. Rather than spend $300+ on a replacement head pipe, I thought I'd risk $49.95 and try to "cut and paste" in a universal cat. I used a "Thunderbolt Universal Catalytic Converter 2" OBD II Compliant..." I found on ebay (the link takes you to the seller's store). It was the shortest one I found and reasonably priced.
To assure that the head pipe would line up with the exhaust header after welding in the new cat, I used a jig. I made two steel plates with holes drilled on 3.5" centers, bolted them to each flange and then joined the plates with a third section. So when I cut out the bad kitty, the flange hasn't moved from it's original position.
The photo below shows the bad cat removed and the flange "floating" in it's original position.
The new and the old converters.
After determining how to align the new converter to the head pipe, I shortened it at each end so that it was about 1/2" longer than the old section I cut out (sorry, no photo.) I then made cuts into the ends with a band saw to create tabs, and bent them inward with pliers to fit the top and bottom diameters of the head pipe. Bending in the tabs reduced the overall length of the new cat, which is why I added the extra 1/2" in length. The result was just enough overlap of old pipe to accommodate the welds.
Top and bottom fit after sliding the new converter into place.
Welded in and ready to install.
The flanges lined up perfectly to the exhaust manifold, the P0432 code didn't return and I passed the emissions test the following day!
When I bought the Jeep in 2011, the P0432 was part of the reason the previous owner was selling it. A dealer had told him that all 3 cats needed to be replaced at a cost of over $2,400.00. It's such a shame.