Hello, I'm trying to revive a US market 1994 Land Rover Discovery V8i that I purchased recently.

The cats had been stolen off it before I bought it, so I had to get a new Y-pipe.

The new y-pipe doesn't fit the best unfortunately, and the catalytic converter on the right hand side is interfering with the front drive shaft in a big way [pic attached].

Normally in a situation where exhaust hits something I'd just take a hammer to it and get clearance that way, but I don't think I should be hammering right on a catalytic converter.

What would ya'll suggest? Maybe I cut the pipe into multiple pieces and put a couple of flex adapters in to shift it over a little? Not really sure how to approach.

Thanks!


Picture of cat pushing hard into front drive shaft.

 

The cat on that side is usually not a round cat (like the drivers side) due to the clearance of the driveshaft. It should be more square and taller than it is wide. Where did you get the Y Pipe?

 

That would make sense that it's supposed to be taller than wide. I got it off rockauto.com.

 

Gotcha yep that cat is taller vs wide for sure! Never have bought cat's from Rock Auto, but I'd look into a refund as that won't work.

 

I guess I would cut out the cat and weld in a piece of pipe or flex. The heat from that cat can degrade the drive shaft, especially if it is really close.

My '94 came with the innards busted out of the cats, so less heat there. No downstream O2 sensors on the 94 so no codes with straight pipe or empty cats. Of course follow your local regulations.

 

Fixed it
Shhhhh 🤫

 

I gotta wonder if that is a real fix, because the cats do not line up in straight lines. I think the pipes need an S-curve. Did you have a jig made to align everything?

 

Stop the BUS..... The US market introduced in 94 & 95 (first and last years with the "dizzy", they are identical in engine and exhaust systems. D1 3 door in Europe in 87.
Replace both Cats with Magnaflow's 94305 "universal Cats", they are very close in piping diameter being LR's exhaust is metric, MagnaFlow is "Imperial"
These "High Flow" Cats fit these Disco's and flow equally a set vs the fat round left & flat right Cats LR installed which do not flow equally in back pressure. Last set I installed on my 95 D1 (5-speed) I recall $87 each, I had to have a friend in Texas purchase then ship to California being not allowed on the 4.6, Mark Adams chip, Bosch 4-hole injectors vs Lucas dribble injectors.....Thirty years ownership, DIY maintenance and counting.

Crappy Kalifornia **** smog laws eliminated seven manufactures Cats sold in Kalif. with only two brands, one a POS Cheapo Cat, the second Made in Chyna. It gets better, replacing a OB1 Cat vehicle in Kalif. they passed a law only OB2 Cats can be installed some 8 to 10+ years ago (?). My cats are 17 years old (MagnaFlow 94305 Cats) still working like new passing smog every 24 months.

Second word of advice to LR owners in Kalif. with new MagnaFlow 94305 Cats to replace the stainless heat shield with new dates of manufacture after the law went into effect with the older shield date codes before that law went into effect avoiding those expensive as well increased flow restriction of these OB2 Cats.

I have installed a couple MF 94305 Cats on special close friends needing replacement Cats installing older heat shields dated before the OB2 Cats installment requirement.
Any slight diameter smaller the Disco piping gets the hydraulic exhaust tubing expansion tool enlarging the pipes slightly to a snug slide fit into these Cats vs a 1/16" ,3/32" to at times 1/8" smaller diameter than the Cat's inlet & outlets. I like to keep the exhaust flow as smooth as possible in gas (exhaust) flow, the same with Port Matching the intake to the heads (both need massive alignment correcting) as well the heads to the cast iron exhaust manifolds, exhaust manifolds to the header down tubes. Smooth gas flow increasing Hp. and Tq. and overall engine performance. Borla Cat Back Exhaust in Stainless, lifetime coverage letting the engine breathe also not being loud just sweet exhaust sound music.

Make damn sure the dizzy vacuum advance is funtioning and not leaking or ruptured as you have a tiny hole nipple at the throttle plate the vacuum signal can be lost being a flow restriction at the plemun top nipple.

Aust. and Europe have the most vacuum advance degrees, US Federal has fewer degrees advance, Kalifornia less degrees vacuum advance than Federal. Spring curve kit, trial a error causing ignition advance to begin sooner (lower rpms) as well a quicker advance curve waking up these engines unless you have a Sun Distributor Machine. Don't wast your time on a 3.9, get a 4.6 block then mill the block for Top Hat flanged cylinder liners. A bullet proof engine vs dropping liners. Hell a 4.8 or 4.9 but not some butcher job installing a Chubbie engine in a disco. You want Tq. for these heavy vehicles.
Restrictor added reducing hot water flow to the plate under the throttle butterfly allowing a slightly warmed inlet air vs HOT to the plenum chamber, reduced detonation issues as well more power produced with denser air sucked in.
Ram cold air intake vs that tiny intake snorkel sucking in hot under hood air. Offset two 3" ID rubber 45 degree intake tubes that draw air by sticking ahead of the radiator support app 5/8" thru the left headlight hole used to replace the left headlamp. Cold dry air behind the headlight, no rain water, higher pressure, impact air driving 30 to over 100 mph, top end i'm not mentioning. The tailpipe bell below the bumper is straw to ice tea in color the stainless is that hot that far away from the engine and running too lean just breathing way better than stock.

At 6 degrees BTDC with plus or minus 2 degrees in Kalif. smog checks I hold at 8 degrees BTDC.

Oh, slot the TPS allowing slight rotation increasing the voltage signal to the ECM thinking add more fuel richening up allowing the engine to run cooler plus run a app 185*F stat, your engine will thank you.
I run a 3 qt. MasterLube Pre-Oiler, never a dry start even after an oil change with the empty 34 oz. oil filter, 38 psi holding for 6 to 8 seconds (air temps depending) before starting the engine, this an electronic timer with relays, Red/Green dash LED light, simple the wife can operate the first morning cold starts.
Yes a gearhead to the max and owner of the 95 D1 5-speed. After road testing automatics no way wifey included an automatic, she drives a 69 Porsche, like me manual transmissions only....
Several years ago I posted my intake extensions I milled out along with testing unit for equal flow 4-hole injectors from 400 to 6,000 rpms simulated. A set og eight injectors within 0.0075 (3/4% flows). I was called out and accused of plagiarism. Machine shop background, aviation mechanic (R2800 Pratt & Whitney rebuilding as well runup teststand certified.
I pass Kalifornia smog legally being "Too Clean", I pass the visual test before the sniff test, ported and port matched cast iron exhaust manifolds vs headers causing critical eye visual inspections trying to fail the visual especially with headers installed.
Sorry end of novel.......BTW, factory "lifetime" suspension and ball joints, added Zerks to fill the grease sacks full, at 142K miles all joints still stiff vs replaced a couple times due to no lubrication, dirveshaft splines and U-joints a shot of grease at every oil change (2,500 to 2,800 local or highway). Street only no dirt, suspension able to drive the mountain twistes vs on it's lid 30 years ago.

 

Nope, not straight. Pipes taking place of cats have larger i.d., the front i.d. is just a little larger than o.d. of stock pipe and rear i.d. is a bit larger still. Allows for angles. 🙂
I'll get better pictures tomorrow.
Friend set up a fixture before cutting the cats off.
Welded in some sparkplug non-foulers for the downstream o2s. Takes the tips out of exhaust flow. No codes.

 

When your time permits please share what your rig sounds like with the cats removed.

T.I.A.