I'm getting ready to replace the y-pipe section with both cats, and need some advise. Is it best to go OEM on this, or would something like a MagnaFlow be OK? I'm just wanting to make sure that if the MagnaFlow is OK that it's not going to be loud or sound like a cheesy V8.

 

if you go on u-tube i'd be willing to bet someone has put up video with magnaflow or borra exhaust on a disco. I "believe" there is a company Davico that which sell a stock style replacement

 

Walker and Davico make OEM style y-pipes. You can search for better pricing but here are the part numbers: RockAuto Parts Catalog[ID]=0&ck[idlist]=0&ck[viewcurrency]=USD&ck[PHP_SESSION_ID]=41g9sglqe2ue04jatr5bg3opt5

Just be glad you don't live in CA!

 

wow,+450 FOR CAL.

I wonder if the Bosal which has a 2 piece y pipe would be better, in that maybe you could twist the pipe and get the converter a little far away from the DS.

 

Just curious as to why you are wanting to replace your "Y" pipe,what year is the truck, how many miles on it and do you have fault codes if so what are they and has the cause been fixed yet.
I am only asking because it is rare to fry both cats.

 

I have code P0420 right now with around 90k on it. From the research I've been doing they need to be replaced around 100k anyways, and there are a couple contributors to them failing before then. I need to do a compression test to make sure I'm not leaking coolant, and I think another concerned area is the injectors. Both of these things I need to check before I do anything. I already have new O2 sensors, new SAI pump since mine is shot, and a new SAI solenoid.

 

You might try performing a few induction cleaning services before spending the money on new cats. A shop that I worked in several years ago had a vehicle that was throwing a P0420. While usually a new converter was the recommendation, this day they decided to do a BG induction cleaning. That cleaned the cat and restored it to efficiency. From then on, P0420s were handled the same way. 75% of the vehicles lost the P0420 after one or two induction services. The remaining 25% had to get new converters.

If you do decide to replace the cats, I have a complete Y-pipe that I took off my D2 after being misdiagnosed by a local shop for an exhaust leak. I got a used pipe from a supplier in another state and installed it even after I discovered that the leak was simply the flange gasket and studs. I am in Columbia, MO.

 

Good point Mike. Cats tend to fail after being run in a car with misfires for some time or after being damaged from impact. The core is pretty tough and gets just hot enough to stay pretty clean. If you dump raw fuel in to them then they can overheat and melt but they don't typically wear out at a certain mileage.

 

am i wrong or doesnt burning coolant also destroy cats

 

It's not the best for them.