Shaking and smells like rotten eggs

INFERNOJK

MEMBER
2017 TOYOTA COROLLA
1.8L
4 CYL
2WD
AUTOMATIC
14,894 MILES

I was sitting in a drive through with my car in D and foot on the brake as I collected my food. Suddenly the car started shaking like crazy. I put the car in park and the shaking subsided. First I looked at my rpm meter which was a little under where it normally is and was twitching up and down fast. The range of the twitch was minute. Then I smelled rotten eggs through my open window. I left the drive through and drove the two minutes back to my office. When I was accelerating the car would shake. Coasting there was no shake. When breaking no shake until I came to a stop. Then the shaking would resume. When my window was open I would get a fainter wife of the sulfur than at the drive-through where it was strong. I decided to drive the car home at the end of the day and drop it off at the service center of Toyota. It's a 14 mile drive and I figured this would be a chance, but, the drive was similar to what I described before. The next morning I drove 1.6 miles to the service center and dropped the car off.

My guess, misfire(s) that let gas into the catalytic converter. I am not sure if I lost acceleration power because I took it easy when driving. The shaking was rather horrible the more I pushed the peddle so I took it easy. Tops of 40 mph when coasting downhill.

What do you all think?

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

The fact that it happened so suddenly, I would agree that a misfire is what is most obvious. It could be a vacuum leak but that would not necessarily cause the smells that you were experiencing. That points to unburned fuel in the exhaust as you stated. The only question is, what is causing the misfire. So sudden like that I would think it is something that affects all cylinders rather than a spark plug. The only reason is, it sounds like more than just one cylinder.

All that to be said, I would be interested if there are any DTCs in the computer. That will point to what the issue is. Could be a Mass air flow sensor throwing off the PCM but that would most likely turn on a check engine light and you didn't mention that being on. If no check engine light, I would think a vacuum leak explains everything except the smells.

Feel free to run what your service shop says past me to see if you want a second opinion of what they say and if it makes sense. Thanks