Actually all was fairly well last night. idling seemed to lessen. Its never had a perfect idle. But i wake up this mornign to take the car to work...and as soon as i start it, it has a continuous screech(to me doesnt sound like a belt) and over 2.5k rpm's gets a massive knock.

Getting quite frustrated. I literally fix one problem and it causes another to set off. I'm now to the point where i just want it driving so i can get rid of it.

I'm not ditching the CAI, because im not putting that much into it. it just got paid off this month, i want it gone. (not trying to be an ***, just very frustrated.)

 

Did the loud screech sound like a dentist drill?

 

a tiny bit higher pitched but yea sort off

 

Ok, that high pitched dentis drill noise is is somewhat normal - it is your secondary air pump if I am diagnosing correctly over the internet.

Now, have you had your valve cover gaskets replaced, or any work done on the engine recently, or at least before this started?

My guess is this - you have an air leak in your SAI system. I'm not sure on the 2.8L engine how it lays out, but there is a comination valve on each cylinder head, these are round, cylindrical items that are near the firewall and up top. One is probably just below the coolant resevoir.

There is an air hose attached to each of these valves that runs back to the SAI pump. Check that hose for cracks and holes. It can be very brittle, so be careful with it.

Next, if you've had any work done on the car, it is possible someone removed the combi valves at least partially to do the work. When I change valve covers, I typically loosen at least 2 of the 3 screws so that I can move it out of the way.

If these screws are not tight enough, there will be an exhaust-type leak, which will often cause a very rough idle.

If the gasket between the head and this valve slid out of place and didn't get put back, there will be a leak and possibly a rough idle.

There are 3 screws holding each to the back of the head. The 3 screws are a realy PITA to get to. My suggestion is to spend $10 at autozone and get a ratcheting screw driver bit wrench. This is a tiny wrench that you can take a short screwdriver bit and slide it in and it locks into place and can be turned with a ratcheting motion. The one at advance auto works great for me.

I put a string through the handle so that if I drop it (and you will) I can pull it back with the string. It makes getting to the screws much easier. You will need a 5 mm hex head screw.

I would remove the valves, find the gasket, carefully put it all back together, and make sure it is on tight.

These 6 screws will EASILY take you 1 hour and probably 90 minutes.

The leak caused by these can often sound like a puffing exhaust or a ticking noise.

 

I just re-read your original post. You mention getting codes, but not what they were.

You then mention that one code was for "airflow".

Could this have been a code for (paraphrasing) "secondary airflow insufficient"?

If so, my last post makes more sense...