I finally ran a VAG-com on my car from the last time i did it and i got a bunch of codes. The last time all i had was one error concerning the EGR valve. This is what i got now

Engine 1

17914. P1506 Closed Throttle Position (CTP) Switch-F60: does not Open/Short to ground

16785. P0401 Exhaust Gas Recirculation flow: Insufficient detected

16504. P0120 Throttle / Pedal Position Sensor / Switch a circuit-G

16522. P0138 O2 sensor circuit. Bank 1-sensor 2: High Voltage

16685. P0301 Cylinder 1: misfire detected

Airbags

00532 Supply Voltage
00588 Airbag igniter- Driver Side- N95

Basically i am trying to get an idea of what i have to fix. from what i understand the EGR problem is worthless for me to fix since i live in a sub-tropical climate. The misfire i believe is from when i ripped one of my magnecor wires from its boot and didn't realize it. Other than that I erased the DTC's and took a 5 mile ride and tried to rescan the engine and it gave me no errors??? Does that mean that these problems fixed themselves or since i erased them they won't show up on a scan ever again. Thanks

first off.... the function of the EGR has no effect or relationship to the climate of the location the car is in.

its an emission device used to lower combustion temperatures to prevent NOx from forming.
w/ that code and a faulty component you will not pass emissions, if your state requires testing.

secondly the difference between the VAG-com and the factory scan tool is the factory one will show the code in a hard fault or a sporadic condition. which means it happened once, and is not happening now. you can delete the code and it won't come back. but still doesn't release the possibility of it happening again.

year / model / engine would help too when describing a problem...

Sorry i thought i had what my car is written in my sig. It's a 1997 A4 2.8L 12v engine, the only mods to the engine are a cold-air intake, a big bore throttle body, magnecor 8.5mm wires, and a LLtek exhaust. Anything modded on the car is just suspension and steering upgrades.

Sorry for not being completely sure what the EGR valve dose for the car. I was told it helps the engine in freezing cold temputures, and if the only problem i would get is that my MPG would decrease a barely noticable amount. The tech basically said i should be in no rush to fix it unless i wanted to drop $500 on parts and labor. There are no emissions control to comply with where i live, so should i fix it or is it fine to leave? Could that be why my exhaust kinda sputters when i slow down in certain gears?

Lastly basically you are saying since I deleted the codes rescanning with a VAG-COM will not pick up the errors even if the problems still exists with the engine?

The codes will reapear if a fault exists. If they don't reapear, that means that there is no problem.