Idle/low rpm vibration( big time)

Gen 2 2007
260k miles
At present no codes.
Previous repairs: coolant switch and pump.

My prius recently started having an intense vibration at lower rpms.It vibrates the whole car almost like a huge subwooferwould. Under heavy acceleration it is gone. When petrol engine is off and regen in process it is also not present.

I found and read LOTS of threads for gen 3 , but does not look like gen 2 has same EGR system, so my "next step" is unknown now.

If air filter is removed for test. . . Issue still present. No visible dents or restrictions in exhaust system.


Thank you for content many of you already provided, and thank you in advance for any assistance.

 

Intense full car vibration. Not a rattle. Like i wear my shooting hearing protection when I drive. P0420 showing now, have a thought on clogged cat?

 

Mpg on highway is normal for my car, 43 mpg. Around town is terrible, but running the AC at idle a lot, so not a fair evaluation, but it is 35mpg avg around town ( normally around 38 this time of year running ac)

I have a 2009 donor car if it helps with troubleshooting.

Side note, do you have a thread on your experience with your lithium conversion?and expierience since then?

Also thank you for your interest and help thus far!

 

Apologies, forgot to answer second part.

Power is fine, zero noticable loss.

 

Updates.

Vibration stopped, fluttery noise now at high rpm. ( lasted week )

Exhaust smell, ( assuming gasket pushed out, resolved possible back pressure issue)

Now mpg around 40 ( drive batteries not doi g so well)


Amazon high flow cat been en route /on order ( some times things take a long time to get to a village in Alaska)


Plan to ride this problem and thread out in case it helps anyone in the future.

 

High flow Cat installed today. . . In the second snow of the season. . .

Overall went well.

Dohnut gasket was damaged and pushed out with some frayed bits.

Cat was clogged 50% or more on front end.

Pre install: stinky cab at low speeds or idle, 33ish mpg, ugly flappy ( exhaust leak. Oise) at heavy acceleration.


Post install: 40.7 mpg :0D, no more in cab stink ( new pipe heating up smelled first 5 miles) old gasket
old cat front end
new cat front end
happier mpg and smell

So unless someone has a question this thread is done.

 

Its from burning oil, it will happen again.

It is not white ( camera flash) not much natural light 11pm in Alaska interior.

Granular items are likely build up knocked loose in my sawsall vibration attack

About 160 miles in so far, happy as a clam.