P0430 Catalytic Converter
 

Hi, new member here. I recently acquire a 173K - 2001 BMW X5 3.0i with 5-speed MT.


Check Engine Light is ON with the dreaded P0430 Code Catalyst System Efficiency Below Threshold (Bank 2).


Here are my Questions.



1. Can the rear exhaust manifold be removed without removing the front
exhaust manifold first? The plan is to remove all nuts from top, then twist/turn the manifold down to clear. Can it be done?


2. Is Bosal replacement catalytic converter any good?

Thanks for any suggestions you can offer.

2001. 3.0i??? Ohhh....nooooo! Sell it imediatelly and get 3.0d or at least 4.4i! 3.0i takes almost the same fuel like big engines and drives like a pregnant cow from 0-100! Even diesel goes better than 3.0i! Get fl diesel from 2004.chip it up and u will get about 250hp! Throw away catalysator! Cut off rear mufflers or just make mufflers empty and sound will be like 4.8is! For diesel it goes like a rocket from 0!

Here u can hear sound inside my office for short moment: https://youtu.be/PH_XXzIGJE4

At first u will need to take off the front any way (not sure) u have to take off 'metal plate' at front!

None of this is possible in NY.

Greatest country in the world :D

All possible in Texas. But that is not the point.

The real problem is that an OEM-style replacement manifold/cat combo costs ~$300 for one because of the ridiculous high mounted integrated cat to make ULEV certification.

This is likely at least 1/10th or more of the value of most 3.0s still in operation. And it only returns you to stock, which as our Latvian friend points out, isn't ideal.

I have been trying to figure out how to do headers and bullet cats for both sides (if one cat goes out, the other cannot be far behind), but everything I can come up with is custom and requires welding. But it comes in under $300.

Did you make sure your oxygen sensors are outputting normally by checking the PIDs? Does it smell terrible and have a hard time making RPMS over about 2500? If the 02 sensors are good and your cat really is dead, then changing just the one may be the cheapest but possibly not the easiest option.

Sorry I can't answer the important questions about getting the rear manifold off without taking off the front. I'm going to do both.

Sidebar - ground level smog via half-burned hydrocarbons, N0x and S0x is all bad and carcinogenic. Catalytic converters are good and the right one doesn't hinder performance. Manifold design can, but to be honest the 3.0 doesn't make any more useful power below 5k no matter what manifolds you have on it, particularly if you are pushing a 4500lb truck with it.

Do the world a favor and use working cats. No one's kids need cancer.

Thanks for the quick response. This car is a project car and my first BMW.

Already have changed all four(4) oxygen sensors and codes keep coming up. I checked fuel trims STFTs and LTFTs they all looked good. The only thing I notice is that the B2O2S2 fluctuates which is a sign of failing catalytic converter. I have not tried Cataclean yet but I’m a little skeptical of its effectiveness and definitely will not be using lacquer thinner.

Exhaust does not smell terrible at all and car runs beautifully. It is just this code keeps coming up after driving about 150 miles after I reset with PA Soft. I am very handy with tools and have a few tools at my disposal. I am leaning towards getting a universal catalytic converter and welding it myself (I have a MIG) but the price of the direct-fit Bosal (< $300 / piece) is not to far off from a universal one. I will have to remove rear exhaust header and see for my self if it is possible.

Thx

Hahaha. I wish I can afford a Diesel X5. That car commands a premium here in NY. About the exhaust manifolds, I will remove the back first and see if it possible to take out. The reason why I got this car is because of BMW's legendary inline 6 cylinder. It is also the model that comes with a manual transmission. I can go for the newer 06 model but that is beyond what I want to spend on a project car.

I already removed that metal plate you are referring to when I change the front differential oil. I can't recall getting more room in getting to the exhaust manifold nuts from the bottom with that plate removed. I think it is a lot easier to remove these nuts from above by removing the huge windshield washer fluid tank out of the way then use a socket with short extension. I will have to make sure to hit the nuts with huge amounts of penetrating oil (few days prior).

If you have a MIG....

M50/M52 manifolds bolt to an M54 head, provided you use manifolds with a single flange, and they do not drop straight down from the head off cylinder 1 and collide with the A/C compressor. People have put earlier engine headers on E53, but the problem is clearance, as you already know, not really the flange. The thing about the flange is there are not studs/bolts in every hole on the E53 M54 head, so to get enough clamping, it is said, you have to use a single flange design and use all the fasters available.

Thanks for suggesting the M50/M52 manifolds. I will research if this will be a better alternative.

The 3.0D was not sold in the USA -

Even in Texas its not possible lol

Anything can be had for a price.

^Considering you are in the last frontier of freedom, I believe you - :)

^ You are always welcome. Swap snow and taxes for a little bit of chaos and legitimate Tex-Mex cuisine. It'll be good for you.

Just an update. I was able to get the car barely thru inspection last year but now it is time to replace the catalytic converters. Both codes P0420 and P0430 show up after driving 100 miles and monitors no longer set for the car to pass inspection again. I also monitor for a year the post oxygen sensors and also the temp before/after cat. So, I got new Walker 16522 and 16523 for $1020 ($510 each) . I will be installing it soon. I am not looking forward doing this job due to very tight space. I will be removing the bottom stiffening plate and give all the exhaust nuts spray of PB Blaster.

The rear manifold, I can get to all the nuts. I am just hoping my arm is long enough to reach them with a socket.

The front manifold could be access from top and bottom. I saw a video someone got to them from the side by removing the plastic fender well. I will see if I have to go this route.

Anyway, here are the pictures of the new (manufacture date 2013) catalytic converters. I also got 16 brand new copper plated nuts (or are they true copper?)

Update: both catalytic converters removed from the car. Unfortunately, most of the studs are rusted out that 14 out of 16 studs came off the cylinder head. New studs already ordered.

I also have to return the catalytic converters since I ordered Walker but got Eastern. Box label is correct but part is incorrect. Ordered Walker from another online store.

Engine does not burn coolant and no misfire but it burns oil.

For the owners who have emissions and replaced their catalytic converters, how many miles would a decent cat converter (Eastern) lasts if engine burns oil 1qt/1000 miles?

Replaced catalytic converters and passed emissions.

So how DID you get those off? I find this job to be horrible, but not as horrible as driving a MKV Jetta with no A/C.


I for sure rounded one of the nuts off, and it looks like you have to take the entire exhaust off to get clearance to slide the manifolds out. Those stupid heat shields on the manifold gaskets do nothing but get in the way. Oh yes, they tear my gloves.


If I ever get the OEMs off, my plan is test fit the new headers, mark those for aftermarket cats, and chop and weld. Should be horrible.

Yes, heatshields get in the way but doable. There are blind nuts but not impossible to get at. You will need deep socket, regular socket, different length extensions 1/4" and 3/8" socket drivers and sockets. I think the flange bolts are 14mm not sure

Here is how I remove the catalytic converters as i remember it:

1. Put car on ramps (all 4 wheels). If you have access to a lift better
2. Remove the metal plate shield from under the car using 16mm socket
3. From the engine bay, empty and remove the windshield washer tank
4. Remove the EGR valve. (be ready to break that little plastic vacuum tube that runs to the back of the car. Also I broke the pipe that goes to the emission air pump so be ready to have a replacement available also.
5. Remove all four Oxygen sensors (mark all connectors/plugs)
6. Once you have all the items out of the way, you will have more access to all 16 nuts
7. Before doing the work, spray PB blasters on all 16 nuts and let it soak. I keep spraying for a few days to make sure. You can spray all of them from top and under the car.
8. Spray also the four bolts by the flange.
9. Start with the top nuts going from front to back. There will be 8 nuts and you will see that you can only remove maybe 5 or 6 of them. (Don't worry you can get the rest of the top nuts from under the car)
10. Continue removing the bottom nuts from the front catalytic converter.
11. go under the car and remove all four flange bolts
12. From under the car, pull out the front catalytic converter by twisting/turning it until it clears. The swaybar might be in the way so may have to loosen/remove the rubber mounts.
13. Now with more room, remove the rest of the nuts from the rear catalytic converter.
14. Do the steps in reverse to install the converters. But in your case, a new header. I was thinking about this route but my state has emissions so a little fabrication is required to fit dual cats. Also the wiring for the Oxygen sensors need to be lengthened. For me, too much work IMHO.

Note: You will see that most of the studs will come off from the cylinder head. In my case 14/16 came out so I decided to replace all of them with brand new studs and nuts. The studs coming off was a blessing since it makes removing the manifolds a lot easier.


It will be difficult to place and insert new studs on the cylinder head. There is no way to know if the studs are all in correctly; if they in deep enough. Also impossible to install the catalytic converters with those studs sticking out.

Here's what I did:

I have prepped the nuts and studs to be "together" using the old studs/nuts as a guide. What I meant by that is I threaded all the nuts on the studs and then insert them one by one as I mount the catalytic converters in place. Start each nut/stud by hand first to make sure they are going in straight. It will be bad news cross threading the aluminum cylinder head

If you find the nut to be turning instead of the whole stud/nut, use "double" nut then remove the extra nut afterwards.


P.S. I use anti seize on all the studs.
Revised: Removed the size of the nut and provided the nuts/studs links for 2001 BMW X5 3.0i:
https://www.ecstuning.com/b-genuine-...h/11721437202/
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Goodluck.

Thanks for the breakdown on this. The bolts from the manifolds to the midpipe are studs on mine, so I can't just get those out. So, I unbolted the entire exhaust - save that bolt that holds the midpipe to the transfer case. It's amazingly rusted.


None of the studs on my front manifold came out, so that's probably bad for me. I can't imagine how I can wiggle that off with all the studs on. There's about 3/4" between the manifold and the subframe rail.


Fortunately, I don't have to get this thing on the road quickly. It is going to be a ton of work this way, but I have the time.

Whats the update here? I have a very annoying ticking and puffing from my 02 3.0 cats. I need to get on the job soon..

Both of my cats were gone getting both P0420 and P0430 codes. I posted on thread #20 on how to remove the cats.

Thanks for the steps.

Couple questions. Did you have to remove the arm off the engine the attaches to the engine mount?

Did you have enough clearance for your manifolds to drop? I couldn't tell based on the comments.

Did the majority of your studs unscrew off the head verses staying in like the should? I see you ordered new ones regardless.

How long did this take you?

I am looking to get these for my 3.0 2002. Thoughts?
https://www.ebay.com/itm/BMW-X5-3-0L...6/253086527915

See replies in red

Thanks a bunch. Are you saying it's impossible to remove them with the studs in? I would prefer that method.

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I can't really say if manifolds can be removed with studs still in the head. Maybe others can chime in who have done the same job.

I had a P0430 code for a long time. All my IM monitors passes but the secondary air. So I checked the air pump when engine is cold. I feel it blowing. I put a vacuum meter on the vacuum line to the valve and there's good vacuum.

I bought a foxwell NT510 and I activated the vacuum valve while the engine running and pump unplugged. I dont feel any exhaust coming out. I know my E53 2001 does not have a check valve. So exhaust should come out.

I removed the valve and I can see a lot of carbon. I cleaned it with throttle cleaner throughly. Put it back. Code did not clear. However 24hours later the CEL extinguished and all my IM monitors are "green".

I bought a replacement valve anyway, the amount of carbon in the port of the cylinder hear is about 1/4" thick, I dont know how to get that out.

Hope it helps someone. If you see all your IM monitors green except for secondary air, it might not be the cat.

Cat replacements
 

Like you, Chedeng, I'm getting those dreaded Cat codes. Passed inspection last year, but I'm concerned I won't make it next November. I'm hoping my southern X5, avoiding most road salt, will be an easier task than you faced. Given the age of our vehicles, I expect most all of us will be doing this soon. Mine turns 13 tomorrow, and has 215k on the odometer. I'll look through your posts on this thread before I drive off that bridge .....:dunno: