Sometimes what happens when you change enough stuff is, the ECU settings that smoothed out the idle with the dirty throttle body and old gaskets no longer applies with the clean throttle body and new gaskets. It takes days and lots of driving for the ECU to re-learn what settings are optimal if it's not reset.

Usually the way to do a reset is disconnect the battery, either for half an hour, an hour, overnight, or whatever length of time you can deal with, then reconnect the battery, start the vehicle, let it idle for 5 minutes or so (the idle may be rough), then go take it for a spin, driving how you normally drive but maybe throwing in some fast acceleration and higher speeds, not just around town driving. It still takes days for the ECU to fully re-learn and program itself but it should be optimal for the changes after awhile and you really don't need to do much other than drive.


You might also want to check and double-check your work, going back and making sure the nuts and bolts on the manifold are torqued to spec (and borrow a torque wrench if you just guessed at how tight they are, that's not really good enough and you don't want to overtighten a plastic manifold on an aluminum head, throttle body bolts and hoses are snug and completely on, etc.


You could remove the throttle body again and disconnect the Idle Air Control valve (IAC) that's on the bottom of the throttle body and clean that with some intake cleaner, making sure the valve is able to open/close completely and all the gunk is out before replacing it. You can also get a new gasket for it at the auto parts store for a few dollars, though sometimes it's a special order and takes a day or two so get it ahead of time.

You should also make sure when you clean the MAF that you're using cleaner designed for the job that won't leave a residue. Special electronics and sensor cleaners will clean that sensor filament right and won't leave residue, where the filament will get a thin flim of residue if you use say, carburetor cleaner, brake cleaner, throttle body/intake cleaner, etc. and could effect the reading of the sensor and so affect the ECU reading and stuff like idle speed.


Keep in mind that the 1ZZ-FE engine is known to have a low idle issue at higher mileage though, where it idles 100-150 RPM below normal idle speed and so you get a rough idle. It's a problem but doesn't affect much, and so far the cause remains unknown, even though it may just be an air leak in a location that hasn't been pinpointed yet.

 

I had the battery disconnected all night and drove 150+ miles over 3 days. Was hoping that was enough to re learn.

-The throttle body was spotless before I put it back on with a new Toyota gasket.

-I only use the special MAF sensor spray

It doesn’t idle low enough to cause a stumble. Imagine just sitting there then randomly it will have the slightest rough idle for a brief second almost like someone had a real quick shiver hahaha.

I will go over everything again though just in case.


I appreciate the input and tomorrow night when I replace the pcv I will go over everything again.

Hoping maybe I didn’t push a coil pack down hard enoggg or something lol

 

Not that it's necessarily the cause of your problem, but when you say the throttle was clean did you check both sides? Mine looked spotless on the inlet side at 118k miles and I was thinking I was going to skip it on my intake gasket job, but on the intake manifold side it was pretty darn dirty. Night and day difference between sides.

 

I've actually been dealing with an erratic idle for a while now. Just today i checked and cleaned the oil filter to the variable valve timing solenoid. I dont know if it made a difference yet as i havent driven the car enough. I will post an update in a few days.
Here is the link to the video i made. Really easy to do and you dont have to remove anything besides the connector to the solenoid, the 12mm bolt that holds the solenoid in and the 14mm bolt that holds the filter in.

 

Keep in mind that the 1ZZ-FE engine is known to have a low idle issue at higher mileage though, where it idles 100-150 RPM below normal idle speed and so you get a rough idle. It's a problem but doesn't affect much, and so far the cause remains unknown, even though it may just be an air leak in a location that hasn't been pinpointed yet.

What is the Corolla supposed to idle at in Park/Drive/Reverse. I find that Reverse is lower than drive, put park sometimes is higher and sometimes not. I am at 600-650 and 700-750, which is identical to the Avalon, etc. If the front and rear mounts do not produce a smoother idle, then I have exhausted everything. A smoke test was even performed with no signs of smoke.

 

Okay I just solved my rough idle. It was the number 4 coil. But I replaced them all 259.99. for all four coil packs vs 89.99 each. Topped off my trans fluid. And good to go. I hope this helps.