dth0ng69

So basically my car starts fine. But it shakes somewhat moderately when i first start it. and the rpm seems to be in place. But as i drive for about 5 minutes and come to a stop at a light i look at the RPM and its at 0 and it shakes. But it doesnt have a problem acelerating and becomes normal as i speed up again. It never stalled since i replaced the battery and drove it around. I took it to the shop they said its the fuel injector and that would cost arond 350 bucks. I read around and theres so much possible options that could be wrong. Like i can adjust the IACV to idle higher? but i just don't know. I also get very very low MPG for a civic around 18 mpg. does this have anything to do with the low rpm.

thanks alot. im a very new newb to this.