This isn't correct.

 

I appreciate your zeal, but stating that something isn't correct isn't useful unless you can supply the correct info. According to the LR dealer parts dept., the same exact part number is used for the front exhaust for all Discovery II's from 1999-2004. I personally asked for the 2004 and 2002 part numbers for confirmation. Can you educate us about where I went wrong?

 

Sorry, I was eating lunch and was only using one hand to type, I just didn't want people to think that was the case. Here are the range of 99-04 Discovery II front exhaust pipes:

WCD106210
WCD000500
WCD105880
WCD000200
WCD105900
WCD001220
WCD105890
WCD000210

I don't really want to go through describing each one, but just know that there are different(several) downpipes for the 99-04 DII.

 

Must add, any exhaust leaks before the upstream O2 sensors will throw off the engine's F/A ratio while downstream O2's are only for checking how efficient the Cats are functioning......~~=o&o>.......

 

First to go was the stuffy stock muffler and resonator combination with piping with a Borla Cat back system, yes there was a performance increase by the "Butt-O-Meter.
Next step replacing the flat right side and round left side miss matched Cats LR installed with a matching set of Magnaflow's 94305 Cats, OB1 D1. These Cats can handle up to a 377 cu/in engine per Magnaflows literature. Running with complete 94305's vs a pair of gutted out 94305's it was hard to detect the difference in performance, they flow. Again another performance increase as well a 12*F drop in cylinder head temps. Tested with cylinder head thermal probe washer under the spark plugs, now the engine has equal cylinder head temps also left and right banks vs factory Cats as the right bank was running hotter by 8*F. Already installed a larger custom radiator (180 stat) so cooling wasn't the problem as well a matched and balanced set of injectors. Another "Butt-O-Meter performance increase then the biggest a Mark Adams "Tornado" chip now properly fueling the engine. Final upgrade yanked out the POS 3.9 and installed the 4.6 engine. Port blending with minor porting from the ram tube intake to the outlet ends of the exhaust manifolds including the down pipes. Another performance increase. After engine break in time spent recurving the mechanical advance to what the engine wants and can handle hence another performance increase. This a fired by distributor ignition 4.6 allowing timing alterations.
Overall between 1.9 and 2.3 mpg increase depending how i'm stirring the stick, a 95 D1 a 5 speed. Much more fun to drive than a boring automatic. Yup she's a keeper.
This photo will explain why LR engines need a lot of help to run properly as several small improvment details items add up to one large gain in performance without installing a big cam which is useless if the heads don't flow. Picture below shows how ugly the head ports are. Photo from RPI V8. Installing Bosch 4 hole injectors vs Lucas's obsolete 1980's single dribble design another improvement .........~~=o&o>......................

 

You realize your replying to a 6yr old thread right?