So will a Series 2 4.0disco throw engine codes if you remove the catalatyic converters?

 

Don't know for sure. P0420 = Catalyst efficiency below threshold ( Bank 1 ). P0430 = ditto ( Bank 2 )
P0432 = Main catalyst below threshold ( Bank 2 ) . There's a whole slew of codes for catalyst dysfunction out there.
Hope this helps. Ed

 

First, it is illegal to remove the cats and second, it will throw so many faults, your ECU will lock up in open loop and your engine will loose 3 or 4 MPG.
Why would you want to remove them?
Mike

 

The fact of the matter is, as I learned from automotive college, that catalytic converters if in normal operating condition do not in anyway hinder performance. Unless yours are clogged or somehow disfunctional theres no reason to remove them. If you must upgrade, look into what Magnaflow has to offer for catalytic converters. I installedmy magnaflows(because mine were past threshold and it was cheaper then the Y) but noticed very little in performance increase. I'd stick with what you got if they are in normal shape.

 

I toohave gone theMagnaflow cut-in route on a BMWand hadgood results (at a fraction of OEM replacement cost).

When my Diso y-pipe cracked, I picked up a direct fit aftermarket y-pipe unit (cats and all) for a little under $400. It was an easy intall and a great fit.

As the others have said, if your idea is to free up a couple of extra HP, it's not worth the law-breaking efforts.

 

Well I am glad I didn't cut them off yet. But no codes right now from them but I am getting bank 1 and 2 lean, I believe is due to my mass air that ha died. The reason I want to remove is because they are starting to stink pretty bad and I was installing a magnaflow muffler so thought it would be a good time to do something with them if I could and my state does not have any emissions test so I would be fine.

 

So you are running lean and your exhaust smells, how is your tranny shifting between 3rd. and 4th? That is the usuall combination of problems leading to a new MAF. You might want to get that lean burn fixed before you start takeing out your valves.
How many miles on your truck and have you replaced the 02's/
Mike

 

Magnaflow makes replacement high flow cats. Mine were plugged and it runs great now. Got it done for $325.