W12 - keep or repair
 

My 2005 W12 has recently thrown me some catalytic converter codes. There are no driveability issues as of yet, just the codes that are preventing it from passing inspections. The cost to repair has me thinking if I should fix it or sell it? It has been awesome to drive, can't beat the power or smoothness. It's generally been trouble-free except for some front suspension issues that have been resolved. What concerns me is that at 205k miles, what's next? I'd love to keep it and repair it as needed but i obviously don't want a $3k bill each time something goes wrong. I'm handy with a wrench and not afraid of tackling tough jobs but I'm also not equipped for major work like dropping the engine. AudiWorld - any thoughts for what i need to consider in keeping it or repairing it?

It's up to you, you're kind of at the upper end from what I hear those having done, at least as far as the motor goes. If replacing the cats means dropping the motor, I'd look into other preventitive things that are high labor costs to do at the same time. If you enjoy the car and don't want to replace it otherwise, go ahead and fix it. Even with that and maybe a couple other miscellaneous repairs, you can't replace it with anything as nice anywhere near as cheaply.

Honestly, not sure what to say. But then, maybe honestly sell it because...

Go back to your post. The description of what is wrong is vague to me. What codes exactly? Question: are you using VCDS, or some cheap throw away OBDII generic (crap) reader? If the latter, back to my initial reaction. To own any Audi at higher miles--and W12 at about top of heap--you need to invest a little in the tools. VCDS is one of them. If not, then yes, budget maybe 3-5K a year or more.

On your post, I can't really figure out the issue either, or buy into that it really is a cat with a high degree of certainty. You mention cats, but W12 issues around exhaust are perhaps most commonly the sensors, or rather the wiring for the sensors. It is the interaction between the forward (pre cat) an rear sensors that tel the ECU's there is a potential cat issue. Since cat change generally means engine drop IIRC--for the manifold ones up by the motor--I would have a lot more diagnostic data first. VCDS at $200 for example costs maybe 7 or 8 percent of just the engine R&R, besides the cat cost and anything else that gets broken.

I had the dealer diagnose that it was the cats. I've been leaning on them for diagnosis as we have a decent relationship. But, you have a point; I realize I'll have to get a VCDS if I decide to keep it as I can dig deeper than I currently can. My point here is what things I need to consider in determining whether to keep or repair the W12...appreciate your response