• Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech

Mac Or-h Problems

  • Thread starter Thread starter ruger281
  • Start date Start date Aug 1, 2012

ruger281

New Member
Jul 29, 2012
29
0
1
Raleigh, NC
Aug 1, 2012
#1
  • Aug 1, 2012
  • #1
When i bought my car 2 weeks ago i crawled underneath and saw that the OEM mid-pipe was hacked. The old owner cut a square in all 4 cats and gutted them, then welded the pieces back in. needless to say, it was leaking at the welds. So i ordered a MAC OR-H pipe and installed it. I have a leak were it meets both manifolds that i cannot fix. I took it to my shop and they said the factory studs on the exhaust manifold were it meets the OR-H will not work. When you look at the stud it is threaded on both ends(one end threads into the manifold and the retaining nut goes on other end), then there is an area with no threads in the middle. This thread-less area in the middle is to big so i cannot tighten the new H enough because the nut stops at the thread-less area. Has anyone ran into this before? I cannot find aftermarket studs anywere! what can i do?
 
2

2002BLGT

Well-Known Member
Dec 18, 2003
2,945
4
59
Bedford VA
Aug 1, 2012
#2
  • Aug 1, 2012
  • #2
ruger281 said:
When i bought my car 2 weeks ago i crawled underneath and saw that the OEM mid-pipe was hacked. The old owner cut a square in all 4 cats and gutted them, then welded the pieces back in. needless to say, it was leaking at the welds. So i ordered a MAC OR-H pipe and installed it. I have a leak were it meets both manifolds that i cannot fix. I took it to my shop and they said the factory studs on the exhaust manifold were it meets the OR-H will not work. When you look at the stud it is threaded on both ends(one end threads into the manifold and the retaining nut goes on other end), then there is an area with no threads in the middle. This thread-less area in the middle is to big so i cannot tighten the new H enough because the nut stops at the thread-less area. Has anyone ran into this before? I cannot find aftermarket studs anywere! what can i do?
Click to expand...

NAPA has replacement studs that are threaded all the way up , use an external torx socket to unscrew the factory studs , hopefully they will come out if you soak them with penetrating oil for a day or so , maybe a torch to apply some heat will help as well , and take one of the studs to napa and they should be able to get you the correct studs you need, the part # is probably floating around on this site somewhere if you search for it you may be able to find it
 
R

rhs98jeep

New Member
Jun 22, 2010
4
0
1
Aug 2, 2012
#3
  • Aug 2, 2012
  • #3
Would steel spacers work as a temp fix? Thats what I would use for now till you can do it right.
 

ruger281

New Member
Jul 29, 2012
29
0
1
Raleigh, NC
Aug 2, 2012
#4
  • Aug 2, 2012
  • #4
No luck searching for the size, but I actually have the factory bolt specs, so ill run to napa tomorrow. Thanks!
 

ruger281

New Member
Jul 29, 2012
29
0
1
Raleigh, NC
Aug 2, 2012
#5
  • Aug 2, 2012
  • #5
Would steel spacers work as a temp fix? Thats what I would use for now till you can do it right.
Click to expand...

dont know of any steel spacers...were would i find those?
 

ruger281

New Member
Jul 29, 2012
29
0
1
Raleigh, NC
Aug 3, 2012
#6
  • Aug 3, 2012
  • #6
I keep looking for replacement bolts but they keep saying the oem size is M12 x 1.75 x 62mm, mine are smaller...prolly like M10 x 1.50? does anyone know the original size? or have my manifolds been changed....
 
K

Kilgore Trout

Fried or Broiled ?
10 Year Member
Mar 30, 2005
4,749
95
134
Aug 3, 2012
#7
  • Aug 3, 2012
  • #7
Life is too short to do ing exhaust work, take it to a muffler shop. They will fix it fast and cheap.
 

ruger281

New Member
Jul 29, 2012
29
0
1
Raleigh, NC
Aug 4, 2012
#8
  • Aug 4, 2012
  • #8
Kilgore Trout said:
Life is too short to do ****ing exhaust work, take it to a muffler shop. They will fix it fast and cheap.
Click to expand...

yeah i have taken to 2 shops, 1 told me i need new donut gaskets...lol and the other said it would take him a couple days to drop the exhaust and reinstall it.....and this shop is in a bad area, so i am not leaving my car there overnight
 

flstang65

10 Year Member
Dec 6, 2007
1,484
135
94
SE Georgia
Aug 4, 2012
#9
  • Aug 4, 2012
  • #9
If they are too hard to get off, thread 2 correct size nuts onto the studs and focus most of your energy on the stud closest to the manifold for your torque to get the studs out. Some penetrating oil wouldn't hurt too.
 

ruger281

New Member
Jul 29, 2012
29
0
1
Raleigh, NC
Aug 4, 2012
#10
  • Aug 4, 2012
  • #10
flstang65 said:
If they are too hard to get off, thread 2 correct size nuts onto the studs and focus most of your energy on the stud closest to the manifold for your torque to get the studs out. Some penetrating oil wouldn't hurt too.
Click to expand...

Thanks! yeah i have been down this road before, i can get them out just fine with a torch but i am still searching for the correct studs....i have 3 sets on the way though. One of them is bound to be correct
 

Jacob_Royer

Member
Nov 24, 2007
142
1
19
Aug 5, 2012
#11
  • Aug 5, 2012
  • #11
You can run a doughnut gasket on the driverside to fix this. I did on my cobra
And it works fine just had to match one up.
 

ruger281

New Member
Jul 29, 2012
29
0
1
Raleigh, NC
Aug 7, 2012
#12
  • Aug 7, 2012
  • #12
Jacob_Royer said:
You can run a doughnut gasket on the driverside to fix this. I did on my cobra
And it works fine just had to match one up.
Click to expand...

Nice! ill look into that, thanks!
 

Jacob_Royer

Member
Nov 24, 2007
142
1
19
Aug 7, 2012
#13
  • Aug 7, 2012
  • #13
I literally took the driverside of my x pipe in advance auto and the guy let me go
Through there doughnut gaskets until I found a match. It seals it up fine without the
two flanges actually touching. I had some kinda funky studs with shirt threads that prevented
me from tightening mine down without the gasket
 

ruger281

New Member
Jul 29, 2012
29
0
1
Raleigh, NC
Aug 7, 2012
#14
  • Aug 7, 2012
  • #14
sounds like i have the same studs.....worth a try
 

mustang562

Member
Sep 1, 2011
102
1
18
Los Angeles
Aug 7, 2012
#15
  • Aug 7, 2012
  • #15
Im on the same boat. Can you post on here the correct size for the bolts when you find out, I need to change them also.
 

Jacob_Royer

Member
Nov 24, 2007
142
1
19
Aug 8, 2012
#16
  • Aug 8, 2012
  • #16
My 96 didn't have this issue must be a 99/04 thing..
 
D

Deleted member 38176

Aug 8, 2012
#17
  • Aug 8, 2012
  • #17
Jacob_Royer said:
My 96 didn't have this issue must be a 99/04 thing..
Click to expand...

Nope. My MAC O/R H went on like butter (when I had it).
 
You must log in or register to reply here.

Similar threads

J
Exhaust manifold to Y-pipe nut & stud dimensions?
  • joeybuddy96
  • Jul 7, 2026
  • SN95 V6 Mustang Tech
Replies
2
Views
92
SN95 V6 Mustang Tech Jul 9, 2026
joeybuddy96
J
O
Progress Thread LTD-ing
  • OX1
  • Mar 15, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
8
Views
393
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Apr 6, 2026
OX1
O
S
Drivetrain 8.8 Pinion and 302 rear main seal leaks after replacing. 93 5.0 with t-5
  • Steigy4827
  • Jun 23, 2025
  • Fox 5.0 Mustang Tech
Replies
10
Views
687
Fox 5.0 Mustang Tech Apr 1, 2026
Steigy4827
S
Engine Sick of stock TB and EGR spacer...
  • 91GTstroked
  • Dec 15, 2024
  • Fox 5.0 Mustang Tech
Replies
6
Views
707
Fox 5.0 Mustang Tech Dec 19, 2024
General karthief
G
2006 Mustang GT o2 Sensor Wiring Issue Car Bogging/Choking
  • GCantero93
  • Sep 5, 2025
  • 2005 - 2009 Specific Tech
Replies
4
Views
1K
2005 - 2009 Specific Tech Sep 6, 2025
Noobz347
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?