Modified XJ Cherokee Tech XJ (84-01)
All modified tech questions. If it modifies your XJ beyond stock parts ask it here.
Sponsored by:
Sponsored by:

Doug Thorley Header and Pre-cat Fitment

Old 04-11-2017, 01:09 PM
  #1  
Newbie
Thread Starter
 
TheSloMoShow's Avatar
 
Join Date: Nov 2015
Location: Columbus,OH
Posts: 14
Likes: 0
Received 0 Likes on 0 Posts
Year: 2001
Model: Cherokee
Engine: 4.0L I6
Default Doug Thorley Header and Pre-cat Fitment

Hello,


The background...

This past weekend I replaced my cracked head. Because it was off, I went ahead and replaced the exhaust manifold with Doug Thorley Header setup. My pre-cats were also bad, so I bought replacement Catco dual pre-cat setup.



Now the issue...

I doubted the way the pre-cat and Headers mated. It didn't seem like a strong connection. Although the stock exhaust manifold and Pre-cat flanges don't actually touch and mate together, the Doug Thorley and Catco pre-cats were spaced even a bit further far apart. I went with it and installed the rest of the exhaust system.
After installing late last night, I took for a test drive. As FYI, I've had my front DS out for some time and didn't have the intention of putting back in last night anyway.

This is what happened when I first applied the brakes and front suspension compressed...
The differential yoke took a chunk out of bank one pre-cat.
When installing the pre-cats it never occurred to me that the pre-cats were in the way of front DS.






So my question is this....


Does anyone have any experience with installing Doug Thorley headers, and if so, what pre-cat setup did you use?

I'm hoping it's just a faulty pre-cat design (too long, wrong routing of collector and flange, wrong flange design etc.) and that removing Catco and installing Walker or other may resolve. But I'm curious what others have experienced so I can make the correct action to resolve.


Thanks in advance for those who can offer advice.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Thread Tools
Search this Thread

All times are GMT -5. The time now is 12:57 PM.