idle issues

[$200_legacy]

i have a problem with my idle. thisd jus started 2 days ago when i ran a can of bg44k. when i start the car the idle goes up and then it dies. that stops when the car gets to operating temp. also when i pull up to stopsigns with the car in nuetral the car dies. this also gets better when the car is at operating temp. no check engine light on( comes on driving down the highway at about 80 then goes away) any help would b appreciated as this is my daily driver
thank you

[Legacy777]

Why did you use the bg44k? Were you experiencing any problems?

Check your ECU for codes. If the CEL went on, a code should be stored. Instructions to pull the codes can be found on my site

www.surrealmirage.com/subaru/engine.html