Ideas and suggestions to my X5 issue
 

I was cruising home with family from NC after the weekend trip. The SAV suddenly downshifted and lost power. I also heard some poping sound underneath. I thought it was transmission related. I pulled over, walked out and check. When I looked under, the cats were glowing red at the rear section. The X5 could barely keep the idle. I shut it off, called a relative to pick us up and a tow truck to get the X5 home.

This is my initial diagnostic: excessive un-burn fuel get burn in the cat. It might have melted the inside and block exhaust flow. No CEL and no symptom before it happend.

Transportador suggests that I also look for blockage or damage after cats section, that would cause exhaust flow constriction.

What do you think?

I'll find out the cause first and fix it before having the cats replaced.

Sounds plausible. As for the cause... stuck injector or failed FPR? Sorry can't offer anything other than that as I've don't recall seeing a vehicle come in with those symptoms at the shop.

Why u replace cat? Here we usually take them out...and sound is great...plus u get hp :)

In the US it a Federal offense to remove a catalytic converter, and no shop will ever do it. The car will fail every inspection, and even if you bring the car for tire change, and the mechanic will see no cats, he must report it. with annual State inspections, and emissions, you are bound to present your car to a stranger at least once a year...

I am surprised that in Latvia, which is part of EU, they will allow uncontrolled removal of the cats, unless leaded fuel is common there (which i doubt).

TMV, in my line of work, we would usually check for a "potato" in the exhaust - some smart a$$hole shoving a blocking device down the exhaust to cause that specific effect that you experienced and stop the car.

How many miles do you have on your x5?

^Almost 122K miles

Did the catalyst material get knocked loose and dislodged further down the exhaust section somewhere?

Sorry to hear about your SAV.

Are both cats shot?

O2 sensors....are they intact?

Maybe you have an injector thats dumping too much fuel thus causing the cat to get excessively hot and glow. Its highly unlikely that both cats would be clogged at the same time. If both are glowing then like I said you could have some failed injectors. In any case you got to hookup the scanner and see what codes come to life and begin the diagnosis from there.

No code from OBDII reader, except a pending "P0111" which is Intake Air Temperature code, that I think is unrelated.
INPA stop working after I select E53 -> Engine -> N62. So I have no code from INPA
GT1/DIS shows no code related to engine, only pending/stored codes from PDC, and LCM.

I'm at a dead-end now. I did start it this morning. It was struggling the first try but started on 2nd try and every time after that. It drives around the block just fine.