My First E39 Headache...cat Problems - BMW Forum

boeuf · 06-14-2005, 10:32 PM

this is my first headache with my car, today i took my 97 540 6 speed to the dealer to check out a check engine light, it has under 115k on it, what they came up with is that my right catalytic converter is finished and my left catalytic converter is on its way out and i will need 4 new o2 sensors . they gave me a rough estimate of $1,200 each cat. From what they tell me its not an urgent fix, they said that i really dont have to worry about it till my next emissions inspection. but let know what are my options are, is aftermarket an option or should i just spring for the 2 g's and call it a day? and where they right about how long i have to get it fix. let me know my options

thanks guys

kerby

mrogers · 06-15-2005, 06:59 AM

I just had the cats on my 97 540i replaced last week. Grand total: $208. I bought two aftermarket Magnaflow 53005 cats for $54 each, and then took it to a reputable local muffler shop and they installed them for $100. My power's back, and the car sounds a little better too

It's a much better option than going with BMW's very expensive cats.

rverma · 06-15-2005, 04:31 PM

I replaced the pre-cat O2 sensors on my car several weeks ok. They were OEM parts - $220 for both and I did the work myself. Well worth the job as it helped fix a lot of sluggishness problems. I can't speak to replacing the catalytic convertors themselves as that is going to defintely cost some money. But I wonder if all four of your O2 sensors are really bad.. From what I have read, the post-O2 sensors are merely there to provide a reading on the emissions coming out after the catalytic convertor. If the catalytic converters are bad, then its reasonable to assume the post-Cat's will give a bad reading. I could be wrong, but just wondering if it may make sense to just replace the pre-Cat sensors and see what happens..

Dirty_Tool · 06-16-2005, 12:33 AM

I would be very leary of aftermarket Cats, and I dont say this to down Mrogers, I do hope that the magnaflows work out for you. My personal experience with them however is that they do not hold up well at all. Most will last 1-2 years max and some not even that.

DT

ozarkmark · 07-01-2005, 12:48 AM

I have the same issue with one of my cats - the one that matches up for cylinders 1-3. Is that the right or left? Not sure.

Anyway, the dealer said it isn't that big of a deal but it needs to be fixed because it can mess up the o2 sensors and possibly foul the plugs on that cylinder bank.

My estimate was in the ballpark of $1200 as well but get this - the service guy told me to take it to Midas or some other muffler repair place to save $$$. I sure trust this guy. Is this a good idea though?

LOS · 07-01-2005, 09:03 AM

If you take it to another shop besides the dealer, can you bring your own OEM parts?

I just found a cool website for OEM parts only... I have to say I have never bought anything from them since I just found them.... They have the catalic conv on sale!

WWW.AUTOHOUSAZ.COM

LOS

tacroteau · 07-01-2005, 09:33 AM

Even so at $200 a pop, even if you replace them every damn year, it would still take you 10 years to make the difference pay off. My vote, keep it cheap if it works.

Quote:

Originally posted by ozarkmark@Jul 1 2005, 01:48 AM
I have the same issue with one of my cats - the one that matches up for cylinders 1-3. Is that the right or left? Not sure.

Anyway, the dealer said it isn't that big of a deal but it needs to be fixed because it can mess up the o2 sensors and possibly foul the plugs on that cylinder bank.

My estimate was in the ballpark of $1200 as well but get this - the service guy told me to take it to Midas or some other muffler repair place to save $$$. I sure trust this guy. Is this a good idea though?

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Eric S. · 07-01-2005, 11:03 AM

Quote:

Originally posted by tacroteau+Jul 1 2005, 10:33 AM--><div class='quotetop'>QUOTE(tacroteau @ Jul 1 2005, 10:33 AM)</div><div class='quotemain'>Even so at $200 a pop, even if you replace them every damn year, it would still take you 10 years to make the difference pay off. My vote, keep it cheap if it works.

<!--QuoteBegin-ozarkmark@Jul 1 2005, 01:48 AM
I have the same issue with one of my cats - the one that matches up for cylinders 1-3. Is that the right or left? Not sure.

Anyway, the dealer said it isn't that big of a deal but it needs to be fixed because it can mess up the o2 sensors and possibly foul the plugs on that cylinder bank.

My estimate was in the ballpark of $1200 as well but get this - the service guy told me to take it to Midas or some other muffler repair place to save $$$. I sure trust this guy. Is this a good idea though?

[snapback]358791[/snapback]

[snapback]358839[/snapback]

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I think it's also well-documented that aftermarket cats have a tendency to create SES/check engine light issues. But hey, I am all for cheaper if you can get it to work, especially if it sounds better!

mrogers · 07-02-2005, 11:27 AM

Well I have had my aftermarket magnaflow cats in for three or four weeks no with no check engine lights or anything. They perform great. Like someone else pointed out, even if they only last me two years that will take 10 years to make the difference up to the OEM cats...and I definitely won't have this car much longer than two or three more years, max.