E70 X5 Catalytic Converter Replacement Bank 1
 

My cat melted as a result of a really bad misfire that caused the inner workings (I can hear noise from the cat) to deteriorate. CEL p0420 Bank 1. So I need a front cat. Suffered a massive misfire while on my way home. I was close to my house so I drove it home. Took around 5-8 minutes. When I got home, the cat was glowing red. Indeed it was toast.


These are the parts I used.

Are you replacing with an OE cat? Doenst look like cutting involved. Get it up in the air and start taking parts off!

:)

How long did it take that 'bad misfire' to kill your cat????

I was driving home and the horrible misfire started. I was around 5 minutes away from my house so I drove her home. The crankcase vent was making a high pitched whistle. I ended up replacing the valve cover, gaskets, breather hose, sparkplug seals, OFH gasket, oil cooler gasket, ignition coils, spark plugs, replaced the flange on a thermostat hose (# 11537541992) that started leaking after removal with a Reins aluminum flange. (# CHC0609) Also cleaned out the crankcase with seafoam spray and did a hot oil change w/ fresh Mann filter. Used all OEM parts except for the hose flange which is OE. I think I should be good with maintenance for a while ;)

I'm going to attempt to replace the cat on friday. I got a Aftermarket direct fit part. OEM is too pricey at the moment, plus I'm going to do a muffler delete right after I get the new cat in. Looking to beef up the sound and put in some 4' Magnaflow exhaust tips. :cool:

lol do you understand OE vs OEM?

:rofl: yes. I got OE style, direct fit. It's not OE or OEM, but it should last the life of the vehicle and fit without modifications.

Oh. You bought a aftermarket part- neither OE nor OEM.


"OE style" means nothing- Seriously it means whatever the seller wants it to mean.



When you get it done, successfully, post back what you bought and how it went....

[QUOTE=ard;1156841]Oh. You bought a aftermarket part- neither OE nor OEM.


"OE style" means nothing- Seriously it means whatever the seller wants it to mean.



When you get it done, successfully, post back what you bought and how it went....

That's correct, it's definitely aftermarket but looks solid. Hoping I can get to it without too much of a hassle. I'll post pics when I'm done.

A short term misfire shouldn’t kill a cat. I’m skeptical that’s your issue. I’ve also not really heard of cats making noise, but maybe so.

I was trying to get at that above..a 5 minute misfire?


Cats can break up and rattle.


If he is replacing this only based on 'cat codes', you want to make 1000% sure it isnt something else driving the issue.


Save that old cat after you finish....