So I'm looking at picking up a new 8 for a bit if a project car. Current owner says it runs and drives well, but stalls occasionally, and multiple mechanics have stayed the Cat is failing and needs to be replaced. So far from what I've seen, it idles at cold okay, and I plan on gleaning some more info before making the drive. Now the issue is the car is a couple hundred miles from me and orchestrating a trailer for it would be a much bigger hassle than simply driving it. Is there anything i can do to ensure the bad cat wont damage or kill the engine for a couple hundred miles? I have a sneaking suspicion that the cat may be on its way out, but not completely borked, and the coils definitely need to be changed.

 

Assuming you're right about the coils, I'd replace them. If the cat is damaged/plugged, I'd also swap it out with either a good one, a cat delete pipe or gut the one that's one the car. Personally, I'd gut it as a last resort as it's still worth a few bucks to a recycler even if it's bad as long as the catalyst elements are there. I think if you drive it as is, you're just asking to kill the engine...assuming a compression issue isn't the root cause of the stalling.

 

If you're keen to get an RX8 specifically, spend the couple hundred on a rotary compression tester and compression test it first before you buy it. It will rule out all sorts of issues and save you big money on a lemon, and if you're looking to own an RX8 its a good idea to own a rotary compression tester anyway so it doesn't cost you anything in the long run. Any time an owner says it stalls it should raise alarm bells unless you're prepared to rebuild/replace the engine. Coils will cause misfires at high load & rpm as the most obvious indication they're having issues, but shouldn't cause that much of an issue catching idle from my understanding.

 

I'm not super worried about compression, i plan on doing a couple tests to at least make sure its decent and if i need to replace/rebuild the engine im prepared to do that, I'm getting it pretty cheap and the shell seems good. I'm more worried about ruining what might already be a good (or decent) engine by driving on a bad cat, because I don't have any experience with that. Will a couple hundred miles damage the engine? Is it worth just picking up an obd2 sensor and just keeping an eye on Temps until I can get it home?

 

Oh absolutely all of that is getting done, coils and a midpipe are the first things to get replaced, I just can't do anything about the cat until I get it home. If the cat really is bad, is a couple hundred miles enough to do damage to the engine?

 

Bad cats kill engines and a couple of hundred miles trying to push exhaust through a straw won't do your engine any favors. If it didn't need a replacement before, it might need one after. But if you're planning for that anyway, your call...

 

Forget about being stuck on the road when your safety is at stake. Seriously, this can happen if your cat is clogged enough.

Either make sure the cat is fine, empty it out if it's damaged or just bring a trailer. Not worth it to chance something like this.

 

You can rent a trailer from U-haul, but you have to have a tow vehicle that meets their weight and towing criteria.

I paid $400 to transport mine 180 miles on a flatbed.

If you really want to take care of, and maintain an RX8 properly, $400 is a drop in the bucket.

Good luck.