Slight unevenness/ pulse gone after EGR fix

Have driven the old 2011 Prius a few times this week since having the EGR/Cooler/plugs/PVC replaced last week -- sent it out on a few runs as well to put on the miles. The MPG is still not all that great -- mid 40's. I wanted to put some miles on it to make sure Ok and no head gasket problem --- 1K miles with no oil use and the coolant has been steady. The coolant was steady prior -- but was using some oil and would have been down a bit after 1k miles. I don't usually drive this one much.

What is gone is the slight pulse that we would feel just after the engine would start when pulling from a stop -- it was just noticeable under very slight throttle at maybe 10 MPH. I could not tell what it was -- I discounted that it could have been a miss fire .. but now thinking it was. Any harder throttle -- or speed and it was not noticeable.

We got a misfire code for one cylinder (#2) along with the EGR code (that's why it went in for the fix) ...when we removed the intake only one port was partially open (#2) -- my mechanic said this would have caused that cylinder to react differently ... so I think this is what was causing the pulse .. and eventually the miss code ... although I never felt it miss enough to throw a code.

We have had some form of this for quite a while --- maybe 65K+ miles ... the car now has 215k. We did the plugs at 152k and that did not fix the pulse.

So -- I think if you start to get a slight miss at very low speeds -- cleaning the system may be in order.

 

Have now put 4k+ on the car since the EGR/Cooler replacement .. intake clean. Checking the oil level it's down about 1/3 -- the oil was changed about 6k ago and I'm pretty sure I topped it up after the EGR work ... so I believe 1/3 for 4k miles not 6k miles. In any event that using less than 1qt in 10k .. still pretty good for 216k. Still no coolant usage -- so looks like that danger was missed.