Check engine sign coming up again 1 day after Spark Plugs changed?

Hello Everyone.
I am just here to ask a quick question about an odd issue about what might be wrong with my Prius. So, yesterday morning, I turn on my Prius and it was feeling a bit off but I took it to the store. Once I got to the store, the check engine light went on and the engine started knocking and kind of started shaking the car. Found out it was Spark Plug problems. So, got them changed. The light went away. Test drove the car and it was working great.

So, today, I took it out for a long drive it was fine until we almost reached home. I thought nothing of it because the engine light didn't go on and not much was going on. But when I took it out again and went to the store again, it started shaking a bit but not as bad as yesterday only a tiny bit. So, I stop and check the engine, and it kept running and running. Like after it got the spark plugs changed it got a boost of energy or something. So, then I drive home and the check engine light turns on again. So, I check the oil, it was fine, nothing else seemed to be off, just the engine kept running and running. Gas consumption was fine, and only the maintenance light was on because my didn't go to the Toyota changing place (which probably will be my next stop soon).

I just went out by myself on the car to drop something off at someone's house, and at first the prius's engine was running and running but then as I did a few rounds around the blocks, it went back to normal. However, the check engine light is still on but it runs smooth. So, unsure if it is a system problem or a bigger problem?

 

Well, we got this car second hand two years ago, so not sure how many miles but a lot of miles. The spark plugs were never changed until now. (I made them change the spark plugs...) so maybe 100,000 or more might be on it. It became sluggish a few months back but was waved off by someone saying it was because we leave the engine on too long... Found out most of the spark plugs were wet and rusted.



And does anyone happen to know any shop that does read codes? It would be a great help!

 

I have an autozone near by, I'll go there and ask them if they can do it. If not then to pep boys it is. toyota dealers are a bit far from me... I was out to put gas into the car but the engine light came up and I went home, so I don't know yet.... Could be if it is causing problems, We did check it, and it was running fine. Just the engine was running too much.

I will update everyone tomorrow afternoon of the problem.

 

So, Bisco might be right it might be the 12 volt battery since it is coming up as 11.4-11.9... But I did a diagnostic check and the system says everything is good. I roamed around today, and nothing really happened. So, I am guessing it is a computer error since it was not done at dealer shop...but I think we'll be taking it there any ways soon... so thanks for the help! The battery was the only thing making sound, everything else was running fine.

 

Okay. so second update: My dad told me the person changed the spark plugs but he didn't tell me until today that the coil was burnt out too! I was like "If it was just the spark plugs...." but no, he didn't tell me that it was the coil. So, now that I have all the info, I now know it is the coil and not just the engine....

Thanks for the help peeps!

 

So update: everything is fixed but a code of P0505 Idle control system malfunction but everything is working fine. The person said that they need $1000 to replace that part for that error.... So, I don't think we'll be getting that fixed any time soon.... Thanks a load for the help!

 

So, my problem vanished in to thin air today.... engine sign went poof!