Discovery 2 stalls at only at idle. Sputters backfires and dies Hot / cold doesn't matter.

New IAC / Stepper motor, still stallsRepinned bank 1 sensor 1 o2 sensor previous owner used universal sensor got 4 from Atlantic British, still stallsNew MAF still stalls, tried with MaF unplugged still stalls
Checked for vacuum leaks with smoke tester none found.

Finally I dropped the exhaust after the manifold at the downpipe, lowered it an inch ran it without the cats, idles fine just loud af my ears!!

Could this be plugged / bad cats? Typically I have found a vehicle won't rev in the past not idle with a bad cat,

Input appreciated

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btw truck has 8mm wired and plugs gapped correctly with a feeler gauge

 

If it runs fine with the Y pipe disconnected then I'd suspect the cats or a clogged muffler yes. I had my 95 D1 give me a crazy bogging situation or wouldn't rev past 3K and it turned out to be a broken aftermarket Y pipe cat.

 

So weird,

it Revs fine I have to rev it to keep it running,
with the Y pipe dropped yeah idles fine And Revs

Any input on if I clamp some straight pipe to replace the cats until I can afford a new Y Pipe Assembly, they are quite expensive to ship up here to Canada

 

PO of my 94 D1 had broken out the ceramic through holes in the cats then welded them back closed. Funny that the aftermarket y pipes I found are made in Canada.

 

What brand who makes them?

 

I just did a quick ebay search. Looks like a $300 price increase since a few months ago. Maybe they added the shipping costs.

Made in Canada.

 

OP has a D2. This is the D2 forum. That's for a D1. So don't order that specific piece.