Ive been getting an intermittent p0420 for a while now on my 2003 Disco with 94k. And for the last few days Ive been searching for the best/reasonably priced universal replacement.

When I search for cats by year/make/model I get the usual direct fits ($475ish on up) and for the universals a couple Magnaflows ($106 to $150ea).

Now if I search based on the specs of the magnaflows rather than year/make/model of my truck I get many results ranging from about $50 and up.

Ive been searching for something like this...
2.25" inlet/outlet
about 13" to 16" overall length
4.5" by 6" wide (roughly)
no air, no o2
3 way
5,500 GVW

If it meets these specs it should work fine. Am I right?

The one im leaning towards is Magnaflow 94105 for $69.99 + free shipping.
Its says itll work on vehicles made before 2004. 2004 on would require the HM (heavy metal) version, 99305hm for $89.99 + free shipping.

I need some feedback here. What universal cats have worked for others?

 

Food for thought, used cats can be sold to junk yards for around $100 a piece. THat being the case, you should wonder why a used one is worth more then a cheap new one.
Buy a good hi efficency cat, usually in the $100 range and then find out why your cat died before it take out the new replacement such as too much fuel, oil or coolant leaking in from the engine.

 

You can't buy used cats around here. I thought there was a Federal law against reselling used cats. Couple that with the value used cats have in the recycling market (check what Platinum, Rhodium and Paladium sell for by the ounce) scrap yards tend to do just that with their used cats, scrap them for their value in exotic metals.

I've used Catco 6905's on countless Rovers I've owned. They offer two sizes, a 12 inch and a 14 inch. I advise people with OBDI trucks to use the 14 inch as they only have to be bothered with one bung for the upstream O2 sensor. People with OBDII trucks would find a more comfortable fit with the shorter 12 inch version. It allows plenty of space for the upstream and downstrean bungs for the O2's. Don't worry about whether they will work on either side, they will. Try Summit Racing and see what kind of deal they're running on these cats. You'll be pleasantly surprised.

 

In typical Federal government fashion, the law is confusing and causes more harm than good. They don't want people running around with substandard emissions components, but they won't let you buy a used cat unless the seller has someway to certify that it is still good. I got into a long discussion on discoweb about how dumb this law is.

 

Thanks for the suggestion on the Catco's. Have you ever actually owned a DII running the 12"er. Id want to be certain they wont throw a cell before buying.

I actually found a site (crazyboyauto) that has the suggested Magnaflow 99005HM and has a "Make Us an Offer" option, which is great idea considering the manufacturer prevents any retailer from advertising any price lower than $106.09. I havent actually tried it though.

 

How long should a CAT last on a, lets say, perfect running Disco. Mine has 94K. I dont burn much oil and no coolant im sure. I had to replace the MAF shortly after buying the truck, and im not sure how long it ran on the bad one. Good STI wires and plugs though. Seafoam treatment and a good clean throttle body and ICV. Doing my front O2s next week.

 

I'm quit certain mine are the original equipment 12 year old 170,000 mile ones.

 

Hmm, how many miles were on it when you bought it?? Some jerk off may have replaced them with factory. I dunno, 170k on original is pretty amazing

 

142k. They are absolutely OEM, and look 12 years old and rusty. Don't you be putting the hex on me, now.

 

170k original here too, no CEL. The factory ones really were built to last.