I'm going to be installing a MAC ory on my 99 SS and I've got a couple questions that I was hoping someone could help me out with (seeing as how you can't post anything in the MAC discussion forum )

I'm going to be installing 98-99 LS Off-road Y-pipe to stock tail
Part Number: 43098



First, this will bolt right to my stock manifolds correct?

And secondly, This Y has the O2 bungs welded in, so will I need O2 extensions for them to reach? (and what size if I do?)

Thanks

 

Is this some Mac ORY that's supposed to fit the stock exhaust ?

My MAC ORY (not on the car) will not fit the stock manifolds...

The flanges look correct to mate to stock exhaust, but on my stock exhaust (99) the driver side would need to be way longer. Not sure if >99 year model manifolds extend farther down on the driver side...

Bad30th

 

Hmm... I thought MAC made an ory for stock manifolds.

Looking at the site this one looks pretty different from the ones connected to the headers.

 

That's what I'm trying to find out before I order it

I'm pretty sure MAC makes one for stock manifolds.

 

Yes, that one should bolt right up to the stock manifolds. You are going to have to soak those bolts in WD-40 for a while, and use an impact gun to get the old pipe off. You will most likely break a bolt, so be prepared to replace the studs if necessary.

You might as well just cap the "rear" O2 bungs with appropriately sized bolts since the rear O2s are useless with no cats. You are going to have to get O2simms or Edit the codes out with a programmer, but that is the case whether you leave the rear O2s in or not, so why not save them..

Have fun!

Tommy

 

Well if anyone knows for sure please speak up... I'd hate to go through the trouble of ordering the wrong thing.

 

I have that mac off road pipe....just bolt it up and go, and no sensor extensions-the o2's all stay in the same spot.

 

From looking at a site that sells MAC exhaust, they say the one you're looking at will work on the stock manifolds.

I'd call their tech line and ask - and be sure to ask about their return policy in case it doesn't fit. I'd eyeball it good first before taking anything apart.

To compare :
MAC catted Y with MAC headers :


MAC Y (with cats) for "stock exhaust 98-99"

"98-99 LS1 Camaro / Firebird
High Performance Y-pipes
Our replacement Y-pipe is made with 2½" 16ga. tubing. System with catalytics and all necessary mounting hardware. System is complete to tail kit and includes all O2 sensors hookups where needed.

Off-Road unit will require chip modification.

98-99 C3098 Catalytic y-pipe $399.50 (pictured)
98-99 43098 Off Road y-pipe $199.50 "

Your ORY pic looks like it provides for the additional length where the driver side cat would go, but the pic isn't too clear...

The catted Y in my post clearly wouldn't reach the driver side factory exhaust. (Of course, none of that is directly related to your question - the one you're asking about appears that it would work)...

Bad30th

 

The y-pipe pictured is supposed to bolt up to the factory exhaust manifolds. I'm not sure about fitment, but the ORY for the MAC headers fits well.

 

I have never heard of a MAC ORY, but it looks like it should bolt right up. Sometimes the stock y-pipe is welded to the i-pipe, so that may have to be cut.

As for the O2 bungs, the two back ones are useless. They are there in case you do want to install cats in the future. You will need to plug them. The front one will be used, unless there are bungs in the manifolds themselves, but I dont think there are.