replacing front exhaust on Discovery II
#1
12-28-2012, 01:25 PM
Join Date: Jun 2010
Location: Atlanta, GA
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replacing front exhaust on Discovery II
I just went through the pain of replacing the Y-pipe on my '04 DII and thought I might be able to pass along some helpful info. The reason for the work was because one of my converters was damaged when I accidentally crossed two ignition wires and drove it for 5 miles. The unburned fuel that dumped into the exhaust caused a rattle in the cat and code 420 on the OBD.
I made the choice to replace the Y-Pipe myself instead of paying the muffler shop $300 to replace one of the catalytic converters. This way I would have two new cats and not have to worry about it later, especially since my truck has 105k miles on it. I was able to find Y-pipes from three manufacturers: Magnaflow, Walker, and Bosal. I happened to pick the "exact fit" model from Bosal because I had no idea what a piece of crap company it is (more on this later).
Unbolting the stock Y-pipe is very straightforward and relatively easy with a 13mm socket wrench; three bolts on each exhaust manifold and two at the muffler. I recommend spraying PB Blaster before hand to make it easier on your wrist. Note that the middle bolt on the manifold end is actually a stud, so don't freak out when a headless bolt and nut drops off into your hand.
Getting the Y-pipe out could prove to be easy or virtually impossible, depending upon your specific truck. There are two cross-members on the frame that make it impossible to slide out the Y-pipe. You will have to either 1) cut off the old Y-pipe, or 2) remove one of the frame cross-members. Unfortunately, removal of the cross members on my truck is next to impossible. Each cross-member is held in place by only 4 bolts, but getting them off is a nightmare. I noticed that a mechanic had previously sheared the heads off of 2 of the bots, which was a bad sign. I was able to get 2 of the bolts out with PB Blaster. However, I had to drill out the 3rd bolt and use a 1/4" easy-out tool to remove it, and the 4th bolt broke the head off while using the easy-out. This meant that I had to cut my stock pipe off with a Dremel cutting wheel.
Getting the new Y-pipe in was easy since it arrived in 2 pieces. I was initially surprised when the box arrived, though, since it was advertised as a 1-piece unit. Also, it didn't include gaskets (you'll need to get these from Land Rover) or the 2 bots to connect to the rear exhaust (try NAPA or Ace Hardware). Everything looked okay with the new exhaust, as best that I could tell, so I bolted it in. It then became very obvious that the rear of the Y-pipe was hanging too low. In fact, it was pressing on the rear cross-member. I figured that I could like with it, though. When I cranked the engine, though, I could hear an exhaust leak at the manifold. Further inspection revealed that, although the bolts were snug, the pipes were not seated properly.
I drove it to Meineke and asked them to snug up the bolts, weld the Y-pipe together, and check for exhaust leaks. They put it on a lift and brought me the bad news. They said that my installation was perfect, but the pipe was not shaped properly and would never fit properly because it was about 3" too low in the rear. Even though it was pressing on the cross member it still needed to come down further in order to seat properly at the manifold! Meineke said they could re-shape the pipe in about 4 hours, so I called Bosal about the matter. This royal turd, George, couldn't have cared less about me or their manufacturing defects. In fact, he was rather rude and condescending, and never took any responsibility for their product. Luckily, the etailer I purchased this garbage from has promised to send a pre-paid UPS label so that I can return it for a full refund.
That still left me having to uninstall the Bosal crap and finding another replacement exhaust. Nobody in Atlanta stocks these pipes for Land Rovers, so there was no reason for me to grab whatever was on the shelf. I decided to pass on the Walker brand, since I heard rumors that they might be made in the same factory as the Chinese retards that make Bosal's pipes. Everyone I talked to about Magnaflow had good things to say, and when I called Magnaflow they told me the number of units for my truck that they sold in 2011 and 2012 and that NONE had been returned. And, contrary to Bosal's claim, Magnacor said that this product is manufactured under their roof and not outsourced to any vendor.
I made the choice to replace the Y-Pipe myself instead of paying the muffler shop $300 to replace one of the catalytic converters. This way I would have two new cats and not have to worry about it later, especially since my truck has 105k miles on it. I was able to find Y-pipes from three manufacturers: Magnaflow, Walker, and Bosal. I happened to pick the "exact fit" model from Bosal because I had no idea what a piece of crap company it is (more on this later).
Unbolting the stock Y-pipe is very straightforward and relatively easy with a 13mm socket wrench; three bolts on each exhaust manifold and two at the muffler. I recommend spraying PB Blaster before hand to make it easier on your wrist. Note that the middle bolt on the manifold end is actually a stud, so don't freak out when a headless bolt and nut drops off into your hand.
Getting the Y-pipe out could prove to be easy or virtually impossible, depending upon your specific truck. There are two cross-members on the frame that make it impossible to slide out the Y-pipe. You will have to either 1) cut off the old Y-pipe, or 2) remove one of the frame cross-members. Unfortunately, removal of the cross members on my truck is next to impossible. Each cross-member is held in place by only 4 bolts, but getting them off is a nightmare. I noticed that a mechanic had previously sheared the heads off of 2 of the bots, which was a bad sign. I was able to get 2 of the bolts out with PB Blaster. However, I had to drill out the 3rd bolt and use a 1/4" easy-out tool to remove it, and the 4th bolt broke the head off while using the easy-out. This meant that I had to cut my stock pipe off with a Dremel cutting wheel.
Getting the new Y-pipe in was easy since it arrived in 2 pieces. I was initially surprised when the box arrived, though, since it was advertised as a 1-piece unit. Also, it didn't include gaskets (you'll need to get these from Land Rover) or the 2 bots to connect to the rear exhaust (try NAPA or Ace Hardware). Everything looked okay with the new exhaust, as best that I could tell, so I bolted it in. It then became very obvious that the rear of the Y-pipe was hanging too low. In fact, it was pressing on the rear cross-member. I figured that I could like with it, though. When I cranked the engine, though, I could hear an exhaust leak at the manifold. Further inspection revealed that, although the bolts were snug, the pipes were not seated properly.
I drove it to Meineke and asked them to snug up the bolts, weld the Y-pipe together, and check for exhaust leaks. They put it on a lift and brought me the bad news. They said that my installation was perfect, but the pipe was not shaped properly and would never fit properly because it was about 3" too low in the rear. Even though it was pressing on the cross member it still needed to come down further in order to seat properly at the manifold! Meineke said they could re-shape the pipe in about 4 hours, so I called Bosal about the matter. This royal turd, George, couldn't have cared less about me or their manufacturing defects. In fact, he was rather rude and condescending, and never took any responsibility for their product. Luckily, the etailer I purchased this garbage from has promised to send a pre-paid UPS label so that I can return it for a full refund.
That still left me having to uninstall the Bosal crap and finding another replacement exhaust. Nobody in Atlanta stocks these pipes for Land Rovers, so there was no reason for me to grab whatever was on the shelf. I decided to pass on the Walker brand, since I heard rumors that they might be made in the same factory as the Chinese retards that make Bosal's pipes. Everyone I talked to about Magnaflow had good things to say, and when I called Magnaflow they told me the number of units for my truck that they sold in 2011 and 2012 and that NONE had been returned. And, contrary to Bosal's claim, Magnacor said that this product is manufactured under their roof and not outsourced to any vendor.
#3
01-02-2013, 09:38 AM
TReK
#8
01-02-2013, 03:56 PM
Recovery Vehicle
#10
01-10-2013, 11:32 AM
Join Date: Jun 2010
Location: Atlanta, GA
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follow-up
The Magnaflow exhaust arrived in 2-pieces, which was great under my circumstances. If you can't get your frame cross-member off then this is the best route to take. When you go to the Land Rover dealer to buy your new manifold gaskets, do yourself a favor and spend the $40 to get 6 new studs and flange nuts. The old ones are likely in poor shape and the new ones make installation of the new exhaust a breeze. In case you're wondering, the long threaded end of the stud goes on first, followed by the exhaust, topped off by the flange nut. Note that all 6 studs will need to be secured very well in order to eliminate exhaust leaks at the manifold. Even a single loose stud will cause audible leaks.
The Magnaflow #93689 was a perfect fit for my 2004 truck, and it's my understanding that ALL Discovery II's use the same exhaust, so you should be able to fit this part if you have a 1999-2004 MY. Also, the design of the exhaust is very good, and the clamp provides proper joining of the two pieces without the need for any welding.
The Magnaflow #93689 was a perfect fit for my 2004 truck, and it's my understanding that ALL Discovery II's use the same exhaust, so you should be able to fit this part if you have a 1999-2004 MY. Also, the design of the exhaust is very good, and the clamp provides proper joining of the two pieces without the need for any welding.