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O/R mid-pipe install tips

6706 Views 12 Replies 8 Participants Last post by  gtdan
Just stickied this on another forum, and thought my MM buddies might be able to use it:

For those intrepid do-it-yourselfers, here's some advice on an O/R mid-pipe install.

listen VEEEEERY carefully, as I am about to make some suggestions that will save you so much time and headache, that you will want to name your next child 'groundpounder'

On the day that you're planning on strapping this on, or maybe the Friday evening before a Saturday install, get lotsa beer..

err, wait..

1) take your rig to a muffler shop and have them knock all your bolts and O2 sensors loose. There are 4 bolts out back (2 per side) and 4 studs at the manifolds (2 per side). There are 4 O2 sensors, 2 on each bank, and muffler shops have a special wrench that looks like a big brake line wrench that they slide over the sensors and simply pop them loose. They're MUCH easier to put back on - I actually did mine with a crescent wrench and just put some grunt on them. When the muffler shop did the rear bolts, 3 of 4 stripped, so they ended up cutting them off with a torch (and these were bolts that only had 3,000 miles on them). Imagine how much fun THAT would be hacking away with a saw underneath your rig. Not pretty. But these guys threw it up on the rack, backed off what needed backing off, cut what needed to be cut, and the car was in the air for about 10 minutes total.

2) get 4 new bolts for the rear (and if you need them, nuts for the studs up front). I didn't need the nuts for the studs, but the bolts obviously since mine had to be cut. Makes it SO much easier on the install of the H to be using nice and clean, non rusty bolts.

3) take it slow on the stud nuts up front (both taking them off and putting them back on) and use penetrating oil (WD40 or whatever). If you snap one of these like my buddy did on his 96 GT, much unhapiness ensues and the whole shebang goes to hell in a handbasket.

4) if you have an air impact or an air rachet, make use of it.

5) use a jackstand or wooden block to keep your mufflers and cat back aligned properly

6) if you don't have a long 3/8 extension or two and a u-joint for same, get them before you start. There are some angles on this that you cannot reach in a straight line.

7) for the passenger side of 99-04 (all V8 models, pretty sure about sixers), there is a one-use crush gasket that you should get from your local stealership (PN 2C5Z9448AA ~$20) OR you can get some exhaust sealer pooky in a tube and slack it on where your H where the manifolds bolt up. Just a little insurance.

The new mid-pipe bolts right up in place of the old one, and it's MUCH easier to install because there are no cats in the way. It's still tight, but there's enough room to get it done without too much pain. I did mine by myself and had the old one off and new one on within an hour.

Good luck! If they can't see you, at least they'll hear you!! :p
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Interesting. I've pulled a few stock h-pipes w/ all cats off 20 yr. old foxes and never had any problem knocking the bolts loose or them stripping. Just use a little nutbuster. Also you can buy or make an o2 sensor socket out of a deep 7/8" socket. Or a combo end wrench works on foxes. Maybe your 99-ups are different. But did it on a few 96-98's back when too.
I've never had any problems either, simple 1 hour install
you guys are just prime examples of what livin right with the Lord will do for you! :D

It only takes a couple of stripped bolts or one snapped stud to put this thing right in the crapper. :mad:

Mine was relatively easy and ya, had it swapped out within the hour ;)
you guys are just prime examples of what livin right with the Lord will do for you! :D
I do try :yes
what did you guys do with the air pump/smog pump hose that goes into the factory H-pipe? did you just block it off??
mid pipe

96-04 dont forget to pull studs out of driver side manifold or shorty & replace with bolts. factory studs only have small amount of threads on end (none in middle) & usualy will cause leaks on aftermarket pipes. just my 2 cents
what did you guys do with the air pump/smog pump hose that goes into the factory H-pipe? did you just block it off??
You talking about the o2 sensors?? If so, you install them in the o/r pipe just like you would the factory pipe
naw, there is a line that runs from the smog pump/airpump under the hood down to the middle section of the factory h-pipe.. i've heard of people just blocking them off temporarly
the only thing i suggest is getting o2 sensor extentions bottom line it makes things a lot easier and if and when you go to switch back to the catted for tests it'll take 30mins max
I'm glad I don't live in a state with emissions laws....
lucky.. i'll be tackling an o/r h in a few months :D just gotta get my cougar sold
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