Cadillac CTS-V - OBX headers with magnaflow cat back...help!

Ok, so today I started installing my OBX 1 7/8 catless headers and UMI motor mounts. So everything came apart beautifully, and the motor mounts went in with realative ease. The headers went in ok too, no denting and the steering shaft fits with out a problem, and yes the headers are wrapped. I did however get cheap and lazy with trying to reuse the stock manifold bolts to the all so expected outcome of breaking one off in the head.

Well after I got that out i is time to tackle cutting and fitting the pipes. So I cut the pipes to length and it does not match up to the header collectors. The X-pipe from the magna flow is splitting the OBX resognators too far apart. Basically, I want to know if anyone ran into the same problem and how did you remedy it? Im currently thinking of cutting a V notch out of the piping then bending it together and welding it...?
Thanks in advance!

i'd have to see pictures

I had the exhaust shop fit my catback to my headers. And damn... No rubbing? My headers vibrate on the steering shaft and I've already took a grinder to the shaft. Next step is putting a small dent in the header. Just hurts my feelings to do it.

I had the same problem with my stock cat back. It takes some playing around. The slip fittings weren't perfectly straight but I finally got it to clamp on. The seal wasn't perfect so I put some adhesive backed DEI heat shield I had laying around to act like duct tape and I haven't had any problems.

Honestly your best option is to have an exhaust shop weld the connector pipes onto the cat-back, but then it becomes quite permanent--and who wants to commit, right?

I went with the ugly but functional option since I'm leery about these cheap cats.

You lost me at x pipe with a catback lol

Lol! Weld that shit. Fuck it. Not like it can't be cut later if needed. Who wants leaks...

This is why I got pacesetters

Ok, so today I started installing my OBX 1 7/8 catless headers and UMI motor mounts. So everything came apart beautifully, and the motor mounts went in with realative ease. The headers went in ok too, no denting and the steering shaft fits with out a problem, and yes the headers are wrapped. I did however get cheap and lazy with trying to reuse the stock manifold bolts to the all so expected outcome of breaking one off in the head.

Well after I got that out i is time to tackle cutting and fitting the pipes. So I cut the pipes to length and it does not match up to the header collectors. The X-pipe from the magna flow is splitting the OBX resognators too far apart. Basically, I want to know if anyone ran into the same problem and how did you remedy it? Im currently thinking of cutting a V notch out of the piping then bending it together and welding it...?
Thanks in advance!

That's correct. You can, if you're really determined, make it fit by playing around with the catless connectors (or high flow cats in my case), but you'll probably have to flip the center piece of the catback upside down to get it to work. Of course, that's only a temporary solution, since the catback will be hanging down lower than it should and it'll scrape on everything.

Ultimately, you need to take it to a shop and have them weld it to fit. Cost me about $150.

I had the exhaust shop fit my catback to my headers. And damn... No rubbing? My headers vibrate on the steering shaft and I've already took a grinder to the shaft. Next step is putting a small dent in the header. Just hurts my feelings to do it.

Have yet to start it so... you just made me nervous!

You lost me at x pipe with a catback lol

??? You have never heard of a catback coming with an x-pipe or what? im confused.

Lol! Weld that shit. Fuck it. Not like it can't be cut later if needed. Who wants leaks...

yup!

This is why I got pacesetters

pacesetter = 1 3/4 which is wqhy I went with OBX :-D

That's correct. You can, if you're really determined, make it fit by playing around with the catless connectors (or high flow cats in my case), but you'll probably have to flip the center piece of the catback upside down to get it to work. Of course, that's only a temporary solution, since the catback will be hanging down lower than it should and it'll scrape on everything.

Ultimately, you need to take it to a shop and have them weld it to fit. Cost me about $150.

I have a welder and can weld so Im good there. I will just have to figure it all out tomorrow.


Thanks everyone!

You'll rub. 1-7/8's always do especially with the slightly shorter UMI mounts. Not a big deal though. A little grinding and a little tiny dent and you're good. I just haven't dented mine yet.

When i put mine in, it looked like they were gonna clear but when i started it and drove it, different story... lol

I actually had to dent two primaries.

Thanks to my grinding, I'll def have to dent only one but I can def see why you would have had to dent two. It's a tight ass fit!

(This is why I got pacesetters) Psssssssttt, as long as your prepared to change em in about 5 years....The OBX headers are mint! I had ZERO problems, then again, I got the 1 3/4" primaries. I'ze was a smart boy n thought ahead! that extra fraction of an ince only causes headaches. The one thing I will say is I dont know why they set it up so the the feed pipes of the Y, slip over the retrieving, that and with the band clamps that dont tighten enough on the recieving pipes, you get a slight leak out of the connections and allows for the pipes to slip....couldn't understand why a week later I had a aweful vibrate...pipes twisted in each other and rested themselves on the plate underneath the Y....Lil tighter of band clamps = all good.

as far as fitting up to the X pipe.....the headers and magnaflow were probly never meant to be mated to each other, like everyone else, gona have to do some custom welding. Mated up to my flowmaster down pipe very nicely, actually brought it back a little which was very nice sine the hangers on the cat-back were barely sticking through the grommets

(This is why I got pacesetters) Psssssssttt, as long as your prepared to change em in about 5 years.

You have proof of that?

i went with katech 1 3/4 headers... they were a perfect match to the stock catback..at the end of the collectors they have the flange for the doughnut just like the stock cat pipes. fitment and finish are top notch