u/Feeling-Aspect-3425

Hey everyone! I wanted to ask if anyone else has ever experienced this. Been happening now and then, I’m in 4th gear and put my foot flat then it hangs around 4500rpm and then keeps going. As it does this my speed does still increase. I do have an aftermarket intake so I’m not sure if it’s a boost leak but I did disconnect and reconnect everything and the only other thing I noticed is my one spark plug housing is a bit wobbly compared to the other two, so maybe I some tiny leak coming from there. Or maybe it’s just a normal Yaris thing in the cold weather, but it seems new to me! Thanks in advance!