loud constant squeel and CEL.
 

You know when you let air out of a balloon and you stretch the opening to make the loud squeal? my car sounds exactly like that. the check engine light turned on about one hour earlier. the noise continues even one Idle and stopped. and the noise continues about one second after you turn the car off.

no smoke or any other issues on how it drives. acceleration on breaking feels normal.

5 speed MT.

could it be the AOS even without the smoke?

I am afraid to drive it to get the check engine light checked. I turned the car off about 10 seconds after the noise started.
Noise did not change or go away when switching gears

It could be a number of things, but without scanning the codes, any thing would be a guess.

May be time to flat bed it to someone with the necessary equipment to scan it, or find someone with a Durametric system that can come you your house and do it (car does not have to run to read codes).

Not to threadjack, but...

I have an occasional squeal that I thought was the clutch last summer. However, the clutch "feels" fine and grabs when pedal is about 1/3 out, so I'm thinking that it isn't the clutch. It usually only happens when I'm taking off in first gear and only lasts a second or two. As you described, it sounds like a balloon squeal.

I finally got my CEL checked today and got codes P1411 and P0410(scan tool said secondary air injection). I'm going to do some research, but thought it may be related to your squeal.

I just started the car again to check if the noise was still there. it started off normally but then I noticed a cloud of smoke behind the car. AOS

I got my CEL checked.

I only have ONE code.
P0410: Secondary Air Injection.

I am still assuming the issue is the Air Oil Separator because of the smoke at start up and the loud constant squeel when engine is warmed up. If anyone has any other ideas, please let me know.

You might have a broken vacuum line in your secondary air injection system giving you the P0410 alarm (might give you a strange sound). As for the smoke at start-up… have you removed the oil fill cap while the car is idling to see how much vacuum is there? Is the cap hard to remove? How does the motor run after removing the cap?

Oil cap was difficult to remove while engine is running, which means a vacuum is being created. But when I did loosten it, the engine almost shut off so I turned the engine off and put the cap back on.

AOS is a pain to remove. I took the back wheel off as well as the plastic cover. But there is little to no space to put your arm in there and reach the bolts to remove the AOS. The side hose does not want to come off either. I ran out of daylight so I will try again later.

I replaced the AOS.

My word of advice. Take it to the shop. It took me 4+ hours of blind work and lots of bruises and scratches. Even with the plastics and rear wheel removed, once you put your arm in there, you cannot see anything because your arm will block the view. And there is only enough space for 1 arm. It would help to have 10 fingers in there. You need to multi-task with one hand, which is why it took me so long.

Pelicanparts also seemed to miss some steps in removing the AOS that are absolutely required unless you have some special tools. I needed to remove some other parts to fit my ratchet in to remove the two bottom bolts.

After it was replaced, I reset the CEL and ran the engine for a few minutes until it stopped burning oil. I assume it is fixed. I couldn't test drive it because it was 10pm and I would have waken everyone up with my exhaust.