Hoping to get some opinions on my 2014 Prius. I think my cat might be going bad and also noticing an increase in fuel consumption. This car has never thrown a code. Lately, I’ve noticed the exhaust sounds a little louder. (Not as loud as a cat being removed, but like, exhaust leak louder). I’ve also noticed some liquid dripping from my exhaust when running. The liquid also sounds like it’s pooling in the exhaust as I can hear a gurgling in exhaust while running. I’ve also noticed a strong chemical smell coming from my exhaust when running. I have been driving the piss out of this car the past 6 months and have been using it for car camping a lot. Not sure if the exhaust was always this loud and I’m just noticing it because I’m spending a lot more time in and around my car lately. Could be an exhaust leak but with that strong chemical smell coming straight out the tip of the exhaust, plus the increase in fuel consumption, I’m thinking the cat isn’t doing it job like it used to.
When your cat clogs the bolts that connect the exhaust manifold and the cat together are on springs to protect from the movement of exhaust system on rough roads. So these springs will also make room for an exhaust leak when there's too much back pressure from a clogged cat. So if you smell a 1970's pre catalytic converter exhaust smell near the firewall in the engine compartment your flange gasket has failed and it's definitely a clogged cat. There's lots of cat soak recipes online to clean them, but when I learned all this it turned out being a waste of time.
Those could be symptoms of a leaking head gasket. How's the coolant level? How's long term and short term fuel trims? Could indicate a sluggish or bad O2 sensor. SM-A536V ?
Any signs of the Prius Death Rattle? +1 on the engine coolant level - that's usually the first 'tell.'
75,000 I had to look this up but yes, I’ve been having this rattle intermittently a year or two prior. Tried looking into this noise before but couldn’t find the right words to describe what I was hearing. Thank you
I forgot I even made this post until today. But I just learned about the notorious Prius death rattle. I’ve definitely had this issue since I bought the car 6 years ago. It hardly happened the first few years of owning the car. But has been getting progressively worse, especially the past two years. My only glimmer of hope is that my coolant level has remained unchanged, so it’s possibly just a clogged egr inlet manifold, or a bad egr valve. I just started researching this death rattle today so I will have to see what I can come up with. I might just start throwing some parts at it: spark plugs, coil pack, egr valve (depending on price), and see if that fixes things before I do a head gasket change.
New development: I think between the engine noise, gurgling(water) in the exhaust, and the misfire (death rattle), this issue has to be a head gasket. Further evidence points to this because my coolant level never moved in the past… until recently I noticed it go down quite a bit (now it sits at the low setting). So that coolant must be going into my cylinder causing the misfires, and then the coolant made its way into the exhaust.
^ Yeah skip that, just a fool’s mission. Do clean the EGR system thoroughly as well as dealing with head gasket. Presumably never cleaned? I drone on about cleaning EGR at least every 50k miles; your head gasket failure at 75k is cold comfort. see my signature for info, last link is full engine section from repair manual. (On a phone turn it landscape to see signatures)
I would suggest long duration oil changes and acidic coolant have far more to do with hg fails than miles or egr clogging. Six years of early warning means a head gasket alone is risky to the point of foolish. Often oil change guys top it off. Oil burning?
I don’t think so. It had a strong car fax and previous owner didn’t have it long enough to rack up too many miles. It is odd that my head gasket would blow so early…
I never cleaned it in the 6 years I’ve owned it and I’m doubtful it was ever cleaned before. I want to make 100% sure it’s a head gasket before I go and spend a week changing it out.
A leak down test or a bore-scope will confirm the HG diagnosis. Actually... A gurgling exhaust does it for ME. I trust carfax about as much as I trust the evening news to be 'fair and balanced' but presuming that the vehicle has 'only' 75K real US Freedom Unit miles on its real odometer, the previous owner might have neglected the car - or the dealership might have gun-decked one or more of the 10K oil changes. That's right. I trust the Evening News much MUCH more than I trust Toyota dealerships. also.... REMEMBER.... (if) This Prius is a 2014. It's now almost 2026. If you're going by the maintenance periodicities in the manual the car should have had all of the maintenance items performed up to at LEAST the 120 month mark... That's why they're listed by miles.....and months. SO First step will be to do the HG tests - especially if 'throwing parts at it" includes coils and plugs - which IIRC are now overdue for a 'turd gen' and you have to get the plugs out of the way to access the bores. It's Prime Day. If you know what that means then DON'T use Amazon for the parts. There's a smallish BUT non-zero percent chance that you will not get real OEM parts. This is one rare case where I would get them from the mother-ship. Good Luck!
