Best exhaust cats for d1 and d2

salvvia

Well-known member
May 28, 2005
990
39
BIG WHEEL ROVN IN KNOXVEGAS TN.
Whats the best cats for a d1 and d2 besides calico or simeese
And has anybody figured out the best way to run without the check engine light on with the secondary air deleted other than changing out the comp modules.
 

kennith

Well-known member
Apr 22, 2004
10,891
172
North Carolina
I've no idea what the rest of you are on about, but the Magnaflow cats are nice; if a bit fiddly sometimes to install. They'll take them back and swap them out without a hassle if they don't fit right, though. It's all one piece with the Y pipe.

They used to have two models: One that's pretty much industry standard, and another with what I recall to be twice the catalyst plating. I have the latter, but it was discontinued some while back. Don't know if it's been re-released or not. Either would be fine.

I've got a spare DII unit I was about to sell. I've just been too busy to pack it up, but I think I've got the right size box sitting in another room. Shoot me a PM if you're interested.

Cheers,

Kennith
 

discostew

Well-known member
Sep 14, 2010
7,706
1,015
Northern Illinois
My plan is to find a PROM from a truck built for a market that doesn't run cats. I think Australia is one of those markets. So I figure with one of those PROMS installed in the ECM it should no longer be looking for downstream sensors.

It's something I've been thinking about but haven't tried to do yet. I fully expect some problems. Figure I'll be able to work around them.
 

discostew

Well-known member
Sep 14, 2010
7,706
1,015
Northern Illinois
The other idea I've had is some sort of signal generator to make the truck think it's got rear o2s and a fictional cat. Problem with that is you need to get some real info out of them since they use them to make fueling calculations. I'm not sure if putting s filter of some sort in the circuit to limit the voltage swings from the rear sensors would work. The truck is looking for an o2 sensor that doesn't have big swings from rich to lean. After the cats o2 sensor readings should be more steady because the oxygen is being burnt in the converter.