I don't expect anyone to be "interested" in this as it's not very exciting. But, I've found it helpful to read the experiences of other 318ti owners, so I'm mostly posting this to add another data point to the community knowledge base.
So...
I'm finally getting around to having my exhaust system worked on. The catalytic converter has been dying since shortly after I bought the car and giving repeated P0420 error codes. This is not the stock unit, it's an aftermarket replacement. (The history there is a bit of a long story but I won't go into that unless someone really wants the details.) I also plan to replace the muffler because it's just too loud for my taste. The tone is OK... it's just too loud, though probably not by "ricer" standards. heh heh heh
Today I went to a Midas shop to have it looked at and get an estimate. I was aware that the previous replacement work wasn't all that great because my mechanic had mentioned it the first time he inspected the car, but I was still a little surprised when the Midas guy came back into the waiting room and said "Do you wanna see this?" The tone of his voice was sort of like "you NEED to see this." LOL So, I went out and looked under the car.
Oh my gawd...
...the guy who actually does the work was standing there trying to not laugh, it was THAT bad... now I know why a replacement cat AND muffler cost less than $300!
There were 5-6 different pieces of pipe of varying diameters between the seam in front of the cat and the seam before the muffler. A couple were only 3-4" long. I'll have to take some "before and after" photos... it's too hard to describe that mess. LOL And they also said that the existing cat was too small.
The good news is that the mechanic said something about this that persuaded me to use Midas. He mentioned wanting to make it look good so that the next person who saw it wouldn't be laughing at HIM. I think I like that attitude, it's nice to find someone who cares about the quality of their work. Hopefully it wasn't just a smokescreen.
I had initially wanted to get a refurbished BMW cat, but eventually decided on the Midas universal unit because the warranty was the same (5 years, 50,000 miles), and the universal unit was about $250 less. Plus they have the universal unit in stock, whereas the BMW unit would have to be ordered.
I also inquired about the BavAuto unit and this is the info I got:
"The BMW 1461 converter is made by DEC as a direct replacement for the
factory BMW piece. These are new converters, and they have a 2 year
warranty on the converter section itself, and a 5 year warranty on the
pipes and welds." So, I'm having the cat replaced, hopefully tomorrow. Then once I hear it, I'll decide what to do about the muffler.
By the way... does anyone know how far behind the catalytic converter the rear O2 sensor should be?? Or does it really matter? This is the area that he'll be replacing and I doubt that the existing sensor position is where it was orignially. Thanks for any info you can provide!
More news as it happens. :-)
JMJ
Having some exhaust system work done... 
Linear Mode
