I have a 2003 Saturn L300. Recently, the engine dies when I am stopped in traffic. It only happens intermittently. Today it stopped while I was moving forward at a modest speed after being stopped. It has ALWAYS restarted immediately after it shut off. I read some of the posts here about the CPS and checking the codes. I don't believe it is the CPS since those folks reported having to wait a long time to start their cars. Also, I don't think it makes sense to check codes if there is no check engine light showing. A couple weeks ago the check engine light was on and I took it to a shop where they replaced the vent solenoid. The check engine light came on again and I went to Autozone to read the codes. I replaced the fuel cap and then disconnected and reconnected the battery to reset. The check engine light has never came back on again. A few days later my current problem started. I'm reluctant to take the car into a shop again since I don't know when the current shutoff problem can be replicated. Also, I'm worried they will start replacing things that may not be necessary and I'm going to end up spending too much money and not solving the problem. Please help! Thank you!
Try and clean IAC valve
1st if not you need a scanner tool
Vehicles equipped with an engine control module, may require a computer relearn procedure after vehicle battery is disconnected. Vehicle computers memorize and store vehicle operation patterns for optimum driveability and performance. When the vehicle battery is disconnected, this memory is lost, which may result in a driveability problem. Depending on the vehicle and how it is equipped, the following driveability problems may exist: Rough or unstable idle.
Hesitation or stumble.
Rich or lean running.
Poor fuel mileage.
Harsh or poor transmission/transaxle shift quality.
Default data is used until NEW data from each key start is stored. As the computer restores its memory from each new key start, driveability is restored.
Driveability problems may occur during the computer relearn stage. To accelerate computer relearn process after battery removal and installation, specified computer relearn procedures should be performed.