Extremely loud rumble when starting car, havent driven it since.

Have you checked underneath the car to ensure the catalytic converter is still there?

 

For perspective I posted this to PriusChat a week or so ago: "Tuesday morning’s chase was Sonoma County’s second high-speed police pursuit of suspected catalytic converter thieves in one week. The county has seen a remarkable spate of over 100 stolen catalytic converters in recent weeks — usually from Prius models. Petaluma police had received a report from a nearby neighborhood of vehicle tampering by two men in a small, dark vehicle, McGreevy said. When officers spotted that car and tried to stop it, the vehicle sped off at such a high speed — at least 90 mph, police said — that pursuit was quickly terminated. Moments later, the driver lost control of the car, careening across the oncoming lane and into that tree, 150 yards south of the St. Vincent de Paul Church. In the Honda, police found a reciprocating saw and at least two catalytic converters the men were suspected of cutting from cars." https://www.pressdemocrat.com/article/news/thieves-steal-over-100-catalytic-converters-from-sonoma-county-cars/

 

You've been cat-jacked. Somebody went under your car with tools and cut out an expensive part of your exhaust system.

Unless you've got really good insurance coverage it's going to be very expensive to fix, sorry.

 

Crap search engine I guess?

Plenty of links for the reader...

 

Because of this forum, I immediately knew what had happened when my catalytic converter was stolen early in this crime wave (at that point it was mostly a UK phenom.). Yes, it is weird to hear that rumble again. Sorry to hear of another victim; CA required the OEM replacement which is expensive - so glad you have good coverage. File a police report and then give them a call. And look into some of the threads here for info on protective plates to keep it from happening again.

 

You don't need to open the hood to check the catalytic converter. It's underneath the car about halfway down the length. You should see a couple large bulges in the exhaust pipe if the cat was still there.

 

I think if you have collision it may be covered not sure not an insurance expert but not many people carry collision on a 14 year old car.

 

I think you mean comprehensive, and some people wind up carrying it longer than they really ought to vs. the depreciated value of the car, but then it works out.

The bad news is that "it works out" might be that the insurance company looks at the case, agrees that they should cover the loss, then totals the car and hands the insured a check for $3k because that's all the old car is worth.

A couple thousand bucks and no car is not exactly what most people want out of the deal, though it is a better deal than anyone without coverage is getting.

 

Yes thanks comprehensive.

 

It cost 3k to replace mine, and it got stolen twice last year. But insurance did cover both times. You may have to rent a car for a while, though, since in my experience it’s been hard for repair shops to keep enough stock, due to the thefts. And it can sometimes take a few days (or weeks, depending on the extent of the shortage) before they can get one.

After you get it replaced, I’d look into a protective shield to prevent theft. I got one (after the second time my catalytic converter was stolen) from http://www.getcatsecurity.com

 

If insurance totals the car, sometimes they will let you deduct its "salvage value" from the payout, and keep the car and what's left of the check. If what they consider the "salvage value" is low enough, that can work out.

Though I think technically you have a salvage title at that point. In my state, once you can prove you've replaced the cat (and can prove where you got the cat to replace it), you can turn that into a 'rebuilt' title.

 

A Google search is only as good at searching as the person who enters the right information. It's all about the the keywords you use... "Prius Rumble" is exceptionally vague...

But use keywords: "Prius cat theft symptoms" and 1st thing you get is a google card (aka: most common/accurate response) that says:

"You'll notice a loud rumbling or roaring sound as soon as you turn on the engine if your catalytic converter is missing. This gets louder when you hit the gas. The exhaust is not working properly, so the vehicle also drives rougher than usual, often with a sense of sputtering as you change speed." Preventing Catalytic Converter Theft | City of Garden Grove

 

To be fair, that would be basing the search on the information the OP was looking for and didn't have yet.

 

Ugh. I think this just happened to us last night. 2007 Prius suddenly extremely loud like that. And when running it is producing what smells like oily exhaust. Is it safe to drive to the shop for repair, or should I get it towed there? Though driving it would be pretty obnoxious even if its safe and the exhaust smells like it's getting in the cabin. We also have a 2012 and a 2013 Prius c. Should we get those plates installed on those too, or is this theft problem only on older Prius?

 

Safe to drive. Obnoxious as noted, but not unsafe.

The 2004-2009 model is heavily targeted.

On the other hand I haven't heard of anyone going after the 2010+ model or any of the c's. Those cars used newer versions of the stolen part that are much smaller, and consequently worth a lot less at the scrapyard.