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View Full Version : aftermarket cat for 540 questions



salansky
05-09-2005, 07:26 AM
Well I can't take it anymore. The driver's side catalytic convertor in my '95 540 is so loud its embarrassing me and it wakes up the neighbors. I want to order an aftermarket cat and would like you experienced folk to confirm the part number before I do. I was all over the Magnaflow/Carsound site last week and believe I have found the correct one. This appears to be a good free-flowing replacement according to the masses. Does anyone have any other opinions on other brands? Here is the one I found.
Carsound 53005 - Round 2.25" in/out no AIR ----OR-----
Magnaflow 54305 -(same one except mirror finish).

-I have seen some comments that a 94005 Oval shaped is OK, but I don't believe its the same as the current one on there. Any advice?
-I found a local shop that seems experienced at welding and should be able to install it for $50-$60. Does that seem reasonable?
-What are your opinions on changing out both? I don't really want to, but if ya'all recommend it I will surely consider it.
-Do you see any potential problems with the O2 sensor? I don't forsee a problem but definately want to keep it from setting off my check-engine light.

Thanks for any advice - hopefully I'll be able to sneak into the house by the end of the week like I used to be able to do.

-jack

DaCan23
05-09-2005, 08:03 AM
For the V8s some aftermarket Cats have produced problems, dont know which ones, I think the general best bet is the DEC cats but perhaps people have successfully used others.

Whats the cost of the Carsound cats?

Most places use BMW1440 for Drivers & BMW1441 for Passengers as a code for the cats for the 540. Think the DEC ones are around $325 each

Tiger
05-09-2005, 08:20 AM
Try $61 each... Magnaflow is made by Carsound. Whereas DEC is same aftermarket competitor for $265 each.

Tiger
05-09-2005, 08:25 AM
Your research is correct... that is the right cat because I have the same car and wondered what my replacement might cost if I ever needed it.

Why would you want mirror finish? Are you really gonna show off your mirror cat? When our car is so low?

$50-60 is very very reasonable for each cat.

It is best to change out both at the same time so you have equal performance on both side.

No problem with O2 sensor... it is not located in the cat... otherwise Carsound would say we need the one with O2 sensor hole.


Now you said loud... I am wondering if you simply just need to tighten the bolt that connects the cat to your exhaust system... Cat really do not rust out... majority of the time, the connection & bushing that link the cat to the exhaust fails and then it is loud.

DaCan23
05-09-2005, 08:28 AM
Does the $60 include the front & rear pipes or thats purely just the cat? Didnt know there was an inexpensive option like that, at least one that didnt have issues.

Tiger
05-09-2005, 08:46 AM
DEC is cat only... so is Carsound/Magnaflow. You are simply cutting out old cat... and replace with new cat. Cat pipes never go bad... super SS factory pipe stay in place.

salansky
05-09-2005, 09:54 AM
Tiger,
The loudness comes from the inside of the cat - its like marbles in a tin can. Apparently the honeycomb ceramic inside the cat has crumbled and is bouncing freely inside. It doesn't surprise me, I drove for months without hubcentric rings and had the 55mph shimmy bouncing everything.

MBXB
05-09-2005, 11:20 AM
st100ray has a some good shots of his DEC Cat conversion on webshots:

http://community.webshots.com/slideshow?ID=97381781&key=YrcNgK

davechurchill
05-09-2005, 11:35 AM
Folks, what would be the Magnaflow cat model for 1995 530i(v8). I have the same problem with my car and the rattling noise made me took the car to the dealer. Dealer said I got to replace both my cats, he couldnt find any good after-market deals, so now I am looking to get them the after-market cats, and they could fit them on my car......

salansky
05-09-2005, 11:53 AM
Here is their website & recommendation for your car. (Carsound owns Magnaflow).

http://www.car-sound.com/catalog/af_listapp.aspx?VehicleID=34822

-jack

Brandon J
05-09-2005, 12:51 PM
Which ever Magnaflow cats your get, get the ones that are EPA compliant. They are packed tighter for better emmissions, but are still freer flowing. I know of many people who have gotten too [much] free flow cats and they could not pass emmissions. One of the biggest problems is that the cats don't heat up enough b/c of lack of restriction (as well as less inner surface core area) and does not convert the gasses as well.

Just an FYI, otherwise Maganaflow might be a very good decision.

Beemr750
05-09-2005, 01:51 PM
st100ray has a some good shots of his DEC Cat conversion on webshots:

http://community.webshots.com/slideshow?ID=97381781&key=YrcNgK


A O/T quetion:
After looking thru your pic's I stumbled on the "loading thrustarm" one.

Either I missread the procedure or you are doing it your way.As I understand "loading" means the wheel/axle has to carry the weight of the car BEFORE tightening the bushing

Tiger
05-09-2005, 02:01 PM
Ahhh! I c now...

Jon K
05-09-2005, 02:02 PM
Try $61 each... Magnaflow is made by Carsound. Whereas DEC is same aftermarket competitor for $265 each.


I have magnaflow 53005 on my car, i have two of them to preserve true dual exit exhaust... they are good product. Stay away from the Random Technology cats, they aren't that good. But my car passed emissions with the new cats... you should replace both by the way. the 53005 flows 4.2L EACH, you'll be fine.

Tiger
05-09-2005, 02:05 PM
Wow... did you guys see how small that DEC cat is??? Darn! That's tiny cheap ****.

Tiger
05-09-2005, 02:06 PM
Magnaflow 94005

davechurchill
05-09-2005, 02:56 PM
Thanks folks, Thanks for the help...I am gonna get the 94005 for my 95' 530i