99 Grand Am SE

Check your coolant & oil level add if needed to fill line. Get the codes read at a store that can do it like autozone, Let us know what the codes are before buying parts, as it could be something else that that sensor relies on for information and may just be a bad vacuum line or anything else. Checking the lug nuts would be fine too, make sure they are tight.

Took it for an oil change today, added brake fluid and told my dad about the low coolant and he said it might need freeon. Took it to Auto Zone 2 days ago and they ran the computer on it and printed me a little paper, doesnt have any codes. I will take a pic and upload what it says. Thanks for the response btw, alot of mechanics will f** me over since i dont have much knowledge on car maintenance and parts.

Also, ABS and Trac off lights come on too, any idea if it has anything to do with the car shaking and the clanky noise?

The IAC is on the throttle body housing or just behind it. Check those electrical connections. When cleaning the throttle body I also clean the IAC Motor. Both come off, both have gaskets, both get cleaned with throttle body cleaner (CRC). I remove them & use small non metal brushes (bottle Brush set & tooth brushes) all different size to get in the small spaces while spraying with CRC throttle body cleaner. I use CRC contact cleaner (electrical board cleaner) in the connectors and then use Dielectric Grease on/in those electrical connections when reinstalling. Reinstall with new gaskets. There are some vacuum hoses/lines running around it and the intake which would be a little easier to check with the throttle body off so check all of them , make sure they do not have bad spots or are off. One will go the PCV valve pull it and spray Throttle body cleaner threw it both ways until the cleaner coming out is clean and you shake it back and forth and can hear the clicking inside and reinstall. Search all over the engine bay for vacuum lines and looking for leaks (bad spots) & replaced then as needed to. Listen also while engine is running for hissing, air sucking sounds and can also use a small spray bottle with soapy water and mist it around the vacuum lines to make them show up easier and while doing this also spray around the intake to motor areas (heavier thicker spray) to see if any leaks are detected, it may suck the mixture in just be prepared to see it, you may need a flashlight and mechanic mirror. You can do this soapy water test before doing the throttle body & IAC cleaning to find out if you can find the vac leak but I would still do the cleaning on those two item as this needs to be done every so often. Also it can be very easy t find a vac leak or extremely hard to find a vac leak and intake vac leaks may appear to be wet already around that area. All this needs to be done before considering the IAC Motor replacement. The Reading the scanner gives is just before a code would set so if its a vacuum leak it may be hard to fine.

If the vacuum leak is at the intake gasket then it will need a new intake gasket, your engine may have a upper & lower intake gasket set, so if so check both and if the lower is leaking change both gaskets.

I appreciate the help, i will do everything noted and come back with an update, thanks!

Also forgot to mention, the rattling sound whenever i drive through a bumpy road. Could that be the wheel hubs or the brake pads? Ive seen on different threads saying it could be one or the other when it comes to the rattling sound.

About time for some sway bar links, under the front, look at them where they connect on each side right & left, there is set of bushings & bolt on each side, they wear out and jingle, rattle all around and if that is it a new set will also tighten up the front end. Buy the full kit that has everything, bushings included.