So, my exhaust pipe had cracked off where it met the front of the center muffler. To add complication to this, a previous repair had been done to the system. Whomever did it cut off the ball flange connector that joins the y-pipe to the center muffler. This added some extra fun.

Anyway, without further ado...

http://www.discoweb.org/cats/index.htm (minus the cat replacment) is the main guide for this project.

First step was to remove the rear pipe. The back hangar unbolted just fine. The two under the truck were not so easy. I ended up cutting the hanger rods. Having a 2" lift allowed for relative ease in twisting the pipe out the back. I did have to drop the sways though.

Once that was out, I removed the y-pipe. As I read would probably happen, 5 of the studs broke. I read about the PITA horror stories of this situation, but I had a secret weapon:



This baby got 4 of the 5 out really easy. It is fantastic.

Unfortunately, I didnt remove the starter heat shield. I think this slightly tilted the extractor to a funny angle, and I snapped off the stud closest to the engine on the passenger side. 3 cobalt bits and alot of swearing later (didnt know you are supposed to drill metal with oil at a low speed) and I had a nice hole that I was able to get an 8mm bolt into.

Lessons Learned:

- The Titan puller is a great tool for y-pipe studs, but REMOVE THE STARTER HEAT SHIELD FIRST

- Yes, the job still sucks, and I may have been helped by having a lift and bigger tires, but you can drill out studs with the manifold still in the vehicle.

 

Stuff I got for the repair:

- - - 2 sets of 7/16" bolts, nuts and washers for flange connection
-
Note: As you can see those Walker ball flanges total about $20 shipped. Magnaflow and Flowmaster sell what looks to be the same thing for $100. No idea why that is, but I went with the walker stuff



Welded the female flange to the y-pipe:


Welded male flange to muffler (had to cut the flange pipe down...too long). Then bolted it to the y-pipe. Fed the rear pipe in (had to chop some of this off to fit as well) and tacked to the muffler, then removed and finished it off:


The muffler outlet was way too big for the rear pipe, so I had to hammer that into a conical shape (similar to what the discoweb guy did with the flange piece he reused) as I welded. Turned out ok I think.

Once that was all done, I fed it in, and welded in some new hangers (the bar I used is not as thick as stock...hopefully that isnt a big deal). Ill try to get some pics of the full install tonight.

 

Oh one other thing...

Prior to removing all the stuff for this repair, I had codes for:

- purge valve
- fuel temp sensor
- both bank1 (drivers side) o2 sensors

The post cat sensor was obvious as 2 of the wires were cut. I put 2 new sensors into the pre-cat spots, then put the old passenger side pre-cat into the drivers post cat. Basically I now have 2 new pre-cat o2s and 2 old (but functional) post-cat o2s.

Dont know why, but ALL the codes are gone now. I will be making a 40 mile drive with the rover tonight, so Ill have more news on this tomorrow. Not complaining though!

 

Nice work. Great write up.

 

Looks like somebody is getting good use of the welder! good work! I had to do the same to mine but all custom Y-pipe to fit the headers.

 

Haha, indeed! I love having a welder. It is an almost essential tool for the old rover owner.

I bet the headers make exhaust work easy. The pipe must bolt under the truck rather than next to the engine?

Thats one thing about mods...they can make other things easier to work on. Having a 2" lift and big tires makes under-vehicle work so much less of a pain.

 

Yea I got sick of breaking the studs on the manifolds and got a good deal on the headers. I ended up reusing the stock Y-pipe and mounting the new high flow cats on them with adapter flanges... I plan to use stainless v-band clamps at the header to cat connection and then moving the rest of my exhaust and muffler (Flowmaster 40) back probably 10-12" (hope it fits!!!) Then I plan to clean it all up and spray it with ceramic coating to prevent it all from rusting. Should work out pretty good.

here's a pic of the shorty y-pipe


And as far as working under the truck, just imagine having a 5" liftand 35's haha that 5 gallon bucker is sitting under my axle

 

I'm buying this tool.

I was under the truck last week and noticed one of the bottom manifold bolts was broken off. That is the source of where the exhaust leak I was hearing!

Yesterday, I was hunting down an exhaust leak in our old Pathfinder. I was tightening the header bolt and BROKE one of the studs. I only laid on at least 15lbs of hand torque and it broke....hummm.

These issues justify a new tool....

**BTW...nice job!**

 

When I was doing muffler selection, I kept reading how people dont like Flowmaster cause they are very restrictive...worse than stock in some cases? At any rate, the 40 is so much shorter than the stock muffler that I think you should be ok? Also, I see the original y-pipe ball flange section is pretty short. You can see my weld-on piece makes things probably 6-8 inches longer there. The shorter section combined with the 40 should be no biggie I think.

Lol, I cant believe you can fit a 5 gal under your axle.

 

Thanks!

I dont know if Cali has them, but you can drive over to Northern Tool and get one there too.

Make sure you get the "teeth" as far down on the stud as possible!