catalytic converter

[RL 325i]

Just bought this 90 325i with 170,000 miles. Catalytic converter was replaced 3/2005. Invoice didn't specific what brand is the cat. but it was charged $350.00 for the part only.

It failed the smog. NO is way too high in both 15mph and 25mph
it measure 2436 from the 15 mph(max is 767)
1427 from thr 25mph(max is 706)

The mechanics said I definately need a new cat.

Question #1
From the picture, can you able to tell what brand is the cat?

Question #2
I read somewhere that our original supposed to be with two inlets and two outlets, How come mind is not? do they make a difference?



all comments welcomes

[AlpineIS]

I had to replace my cat a while back also. I first went with a unit very similar to yours (at least the cat itself looked similar), I believe it was a DEC brand. The only difference is that it actually came with the dual inlet pipes. Yours looks like it was welded in place. The one I purchased was a direct bolt on.

Although it worked fine and the engine seemed to breather better, it was too loud and I later exchanged it for an original. Since they are expensive new, I purchased a used unit from a junker.

I can't really help you with your diagnosis. I would bang on the cat itself to determine if the honeycomb has disintegrated. If it rattles, then you need a new cat. Otherwise, your problem may be elsewhere. Good luck.

[RL 325i]

Thank you, ApineIS for sharing your experience. I had broswed what I can find on line. I did saw the DEC and they cost about $300-400 range. which is excatly how much the Previous owner pay for... and guess what ..I felt the exhaust a bit noisey too. I think you guess might be right. Being only litter one year old. and it fail the smog so bad, I will agree that there is something in my car.

I will jack the car and look at the cat more and like to suggest to check for rattle.

by the way i found this at Ebay. do you thing this is a real BMW catalytic converter??

http://cgi.ebay.com/ebaymotors/87-1991-BMW-325i-325is-Catalytic-Converter-OEM-NEW_W0QQcmdZViewItemQQcategoryZ33630QQihZ009QQitemZ190024805865QQrdZ1QQsspagenameZWDVW

Thanks again

[AlpineIS]

The cat on eBay is not a genuine BMW cat but is an OE (original equipment) replacement. It is not the exact unit BMW put in your car at the factory but it will mount and function without a problem.

It also has the dual inlet pipes, which is how any cat replacement for ours cars (at least the i engined) should be purchased.

Since I know your state has strict emissions testing you have 3 options if in fact your cat is bad:

1. Replace with an original cat. They are over $1000 new at the dealer so consider finding one at a junker with low miles. It is illegal in many states to sell used emission components but you may get lucky somewhere. Alternatively, you can post a thread in WTB forum. Maybe someone has one lying around they'd be willing to sell.

2. Replace with an OE equivalent such as the one found on eBay or other sites that sell cats. Make sure you buy it with the inlet pipes and not just the cat itself. Your exhaust sound will be louder but you will pass emissions.

3. You can find places on the net that will sell you remanufactured cats. I used a place a couple years ago and they sold me the exact same unit that came with my car originally. I will dig up the receipt and provide you with the company name if you are interested in going this route.

[RL 325i]

I think I am going to get an inexpensive aftermarket like magaflow or something to get the smog done first. My budget is really tight now.

Cause I have to do the steering rack($250.00) Timing belt and water pump($150.) Oxygen sensor ($75) Cat converter($100-$150) plugs, Cap,etc.......and smog again.......All of them are parts only. I am planning to all the work myself. but they still add up.
I hoped I make a right choice on the cat. I am going to get the two in two out from Megaflow for $80.00(match the original OEM configuration) and have someone weld it in for me. Although I don't like it loud but no choice

http://cgi.ebay.com/ebaymotors/Magnaflow-Catalytic-Converter-91-BMW-325-525-528-535_W0QQcmdZViewItemQQcategoryZ33629QQihZ001QQitemZ110019317752QQrdZ1