Catalytic converter red hot & very rough engine after maintenance service

I just got PCV, throttle body & MAF sensor cleaning, spark plugs, and transaxle fluid change done at a local non-dealer shop. The mechanic noticed car running very rough after everything has been done and found out that my catalytic converter is red hot. He told me that the car does run pretty rough after throttle body cleaning and to see if the problem goes away and to schedule to inspect catalytic converter problem later. I drove about 5 miles and stopped because it didn't show any improvement and the burning smell and shaking was just very bad and scary both at idle and acceleration.

I think he might have triggered something like putting a bad plug or done something to the MAF sensor. While I never checked catalytic converter I never smelled anything like what I was smelling today. It was very noticeable smell not to mention the some plastic part around the catalytic converter melted and broke off easily when the mechanic pulled it. I also went to the dealership about 2 weeks ago and did diagnostic and they said nothing about catalytic converter.

Do you think a lot of damage has already been done to the ICE and catalytic converter? Car is pulling less than 15 MPG and the battery is at 1 purple bar.

What should I tell my mechanic tomorrow?

Any input would be appreciated.
Thank you.

 

Dealer mentioned something about rusty plugs and misfire codes -- reason I did these maintenance services. Everything was running fine though except occasional engine light coming on and off. I think it was code for bad gas or something or at least that's how dealership put it at diagnosis before the this recent one. I'm about to the check the exact codes in a minute.

I've been reading online about what causes catalytic converter to overheat and I've read bad misfire and dirty MAF sensor can allow unburned fuel to pass into the exhaust. I just find it very strange that car becomes like this so suddenly from services that supposed to help with the problem.

Also, do you need special code readers (like the ones that arescec mentioned), tool, or procedure to pull codes from a Prius? Because my mechanic yesterday could not find out how to pull codes nor did an Autozone employee.

Well, I hope I get this figured out and fixed up today.

Oh, speaking of getting it fixed up today, do you think I can purchase the catalytic converter locally? If so, where do I have best chance of finding it?

Thank you so much for the help!

 

First of all thank you all for helping!

The problem was MAF sensor. I took the car back to the mechanic and checked plugs were fine. I asked if he could clean the MAF sensor again and he said he has already done it twice because he noticed the car was running rough. He then showed me how it made no visible improvement when he sprayed some more on the sensor; it was still cloudy. As last hope we replaced the MAF sensor with the new one and it ran normal again.

I'm just confused how MAF sensor cleaning spray caused such drastic change to the sensor. The car was running perfectly smooth (except some misfire caused shaking which dissapeared after dealer cleaned the plugs) until I've done the cleaning. I thought the spray was supposed to do good to the sensor not make it worse. Can MAF sensor cleaning spray actually be harmful to sensors that are already in bad condition?

Also, we still couldn't find out how to pull out codes out of my car. We've checked that the port does have power. But his OBD2 scanner did not work nor did O'reily's, Auto-Zone's, and Advanced Auto Part's OBD2 scanners. Is there something wrong with my car's computer that it's not triggering scanners?

Engine light has been on constantly and I really want to check the codes to see it if catalytic converter or any other component related to misfire or fuel/air mixture has been damaged.

Could 10 miles of driving with bad MAF sensor ruin catalytic converter and/or ICE badly? I mean the car was running really scary--it was barely accelerating, shaking hard non-stop at idle, and very unpleasant burning scent from glowing red catalytic converter.

I'm glad the car is normal now but I'm still worried!