[Liquidpaper]

Ladies and Gents:

I melted my catalytic converter from (I presume) track abuse. Don't worry, they fixed it under warranty, but I am going to go get the Fabspeed HJS Cattled Downpipe to swap in from now on -- I can't afford to keep melting these things (BMW might get suspicious).

The shop foreman at Santa Monica BMW called me and said "Yep, looks like a lava flow in there." He was pretty cool about it actually. Props to them.

Anyway, for those of you who track a lot, please be advised...

[BMW GENIUS]

I'm assuming mine will go out at some point sooner than I think at the rate that my car tends to backfire and crack at lol.

[mike@tpc]

you are lucky. My dealer wouldn't cover a damaged tire wear sensor today because I powdercoated the brakes....8500 miles ago!

[Liquidpaper]

Originally Posted by mike@tpc

you are lucky. My dealer wouldn't cover a damaged tire wear sensor today because I powdercoated the brakes....8500 miles ago!

Yes, I did get very lucky. Which is why I wanted to take preventative measures to make sure it doesn't happen again.

[pikcachu]

Originally Posted by Liquidpaper

Ladies and Gents:

I melted my catalytic converter from (I presume) track abuse. Don't worry, they fixed it under warranty, but I am going to go get the Fabspeed HJS Cattled Downpipe to swap in from now on -- I can't afford to keep melting these things (BMW might get suspicious).

The shop foreman at Santa Monica BMW called me and said "Yep, looks like a lava flow in there." He was pretty cool about it actually. Props to them.

Anyway, for those of you who track a lot, please be advised...

How did you find out it happened?

[Liquidpaper]

Originally Posted by pikcachu

How did you find out it happened?

Check engine light came on (code p420). Took it into the dealer, and that's what they found.

[alz0rz]

Originally Posted by mike@tpc

you are lucky. My dealer wouldn't cover a damaged tire wear sensor today because I powdercoated the brakes....8500 miles ago!

Tire wear sensor?

[pikcachu]

Originally Posted by alz0rz

Tire wear sensor?

probably meant brake pads

[mike@tpc]

yeah, I meant brake pad wear sensor. They wanted $200 to change it out and clear the code. I paid $8 for one on rock auto and will have Markert Motor Works here in Atlanta clear the code for me and code the rest of the car for much less.

[Liquidpaper]

Okay, just ordered my new Fabspeed Downpipe with HJS Cat. Hopefully that will fix the problem. I'm going to the dealer today to pick my car up -- if they still have the melted pipe I'll take pictures.

[rwalker]

what are your concerns with not running a cat?

[Liquidpaper]

Originally Posted by rwalker

what are your concerns with not running a cat?

1. Don't want the CEL; and

2. I hug trees.

[rwalker]

Originally Posted by Liquidpaper

1. Don't want the CEL; and

2. I hug trees.

Ah.

On #1: it's likely you'll still get a CEL (eventually) on an aftermarket cat, if history is any guide.

I have no rebuttal for #2 .

[Liquidpaper]

Originally Posted by rwalker

Ah.

On #1: it's likely you'll still get a CEL (eventually) on an aftermarket cat, if history is any guide.

I have no rebuttal for #2 .

I don't think so about 1. It's an HJS catalyst (extremely high quality), which is specifically why I am going with Fabspeed.

[rwalker]

Originally Posted by Liquidpaper

I don't think so about 1. It's an HJS catalyst (extremely high quality), which is specifically why I am going with Fabspeed.

I'm looking forward to hearing how you fare, then. This is a longstanding bugaboo with the N54 and N55.

[alz0rz]

Longstanding bugaboo with many cars, aftermarket 'sport' cats just do not seem to have the durability as an OEM cat used within its limits.

[Liquidpaper]

Originally Posted by rwalker

I'm looking forward to hearing how you fare, then. This is a longstanding bugaboo with the N54 and N55.

Is it really? I didn't know that. Thought it was just me being a maniac. Hm. Still, I can tell people "I DRIVE SO HARD PARTS OF MY CAR ARE MELTING."

[rwalker]

Originally Posted by Liquidpaper

Is it really? I didn't know that. Thought it was just me being a maniac. Hm. Still, I can tell people "I DRIVE SO HARD PARTS OF MY CAR ARE MELTING."

To be clear, the bugaboo is the unavailability of a catted downpipe that works reliably with the BMW ECU on a long-term basis.

[Liquidpaper]

Originally Posted by rwalker

To be clear, the bugaboo is the unavailability of a catted downpipe that works reliably with the BMW ECU on a long-term basis.

Oh.

Still, should be interesting to see if it works or not. And either way, I can't use the OEM pipe anymore.

[Liquidpaper]

You know, I've been thinking about it, and I am not so certain the catalytic converter should have melted here. I've been reading up on the causes of cat meltdowns like this, and normally they are due to engine misfires, running very rich, blown 02 sensor, fuel injectors, etc. My car has none of these problems.

Considering how melted down the cat was, I'm starting to come to the conclusion that this is a design defect with either the cat (or that cat was defective), or this variation of the N55 engine. It just shouldn't have this kind of problem, even from putting the car on track. It's a goddamn BMW. It's not like I'm banging off the rev-limiter all day and putting incredible stress on the engine, or making the engine itself too hot (it actually runs quite cool -- about 240 F) on the track.

Anyone have any insight on this?

[mike@tpc]

this is true. The only time I have melted a cat was when I accidentally switched the ignition wires to 2 cylinders when installing a supercharger kit on my old 350z.

I've got a ton of track time, but all of it is without cats on my 370z racecar. One hard trackday on the 2 and no issues though. If it was from running hard, I don't think you would be the only one, as others also track theirs.

[zipphreak]

http://www.bmwe34.net/E34main/Trouble/Catalyticconv.htm


Most likely too rich, raw fuel hits the hot cat and ignites making it hotter and melts