Problems after serpentine belt change

[Jamiesince1990]

Evening everyone, 

My car is a 2001 1.3vvti Yaris GLS Automatic with 88k miles. 

Scroll down for the too long didn't read version 😃

I took it in last week because the serpentine belt was squealing really bad, it turned out one of the pulleys had come loose, mechanic put threadlock on the pulley bolts to prevent it happening again and changed the damaged belt. 

A new problem has since emerged, I went on the motorway and the check engine light came on, Car was running fine, I took it back to the garage and the code was low oil, oil was checked and was fine, code reset, I went on the motorway again and the light reappeared, drove for the next few days and the light went out, went on the motorway again and the light came on again, the car also seems to be accelerating by itself at times even when my foot is off the accelerator. 

Has anyone come across this issue. 

1. Car was squealing, took to garage, serpentine belt pulley was loose, pulley bolts tightened, belt replaced. 

2. Took car on motorway, check engine light came on, car driving fine. 

3. Took back to Garage, code said low oil, oil checked, oil okay, light reset. 

4. Went on motorway again, engine light came back on, drove for a few days incl motorway driving, light went off. 

5. Coming home on the motorway yesterday light came back on, Car also seems to be accelerating by itself at times when foot isn't on the pedal. 

Any help would be much appreciated! 

 

[Byzii]

Hey there,

Did you see the code vehicle had stored? Or was it just the case of mechanic checking it and relaying to you what he saw?

Also what kind of diagnostic reader was he using? If it's a generic one or from other manufacturer (VAGCOM for example is popular) it could show an incorrect description.

I've never heard of car accelerating by itself but then again I'm not experienced in automatics so others might chime in with more useful advice.

[Jamiesince1990]

Just now, Byzii said:

Hey there,

Did you see the code vehicle had stored? Or was it just the case of mechanic checking it and relaying to you what he saw?

Also what kind of diagnostic reader was he using? If it's a generic one or from other manufacturer (VAGCOM for example is popular) it could show an incorrect description.

I've never heard of car accelerating by itself but then again I'm not experienced in automatics so others might chime in with more useful advice.

It was a tablet OBD reader, he put my reg in to get the model details and it came up with a code that said low oil, then he checked the oil and that was fine, I've since checked it just incase and it's still at the same level, I was with him when it showed up and checking the oil. 

I've driven the car for a week since and there doesn't seem to be any serious issues, just the bizarre accelerating at times and the intermittent engine light, maybe its become haunted haha. 

[m456an]

I had an over acceleration problem which occurred once a week on the avensis I just cleaned the  PCV valve and that was it. Not sure where it is on the uaris though. 

I decided to not correct my spelling mistake above.