Corolla engine problems

rolla123

On my 2000 Corolla with 190k miles has 2 check engine lights came on, one about misfires and one "system too lean". I bought an ignition coil which seemed to stop the mis firing but can't diagnose the "system too lean which I'm pretty sure is code P0171 or something like that. I will go and crank my car and sometimes the whole thing will shake, on rare occasions it'll shake violently even shaking things in the car. And also, again only sometimes I'll put it in drive and go to give it gas and it'll jump forward then start stuttering/hesitating and won't go no matter how far down I push the gas it seems (never have I tried to force it) then I usually just play around with it as put it in park and reverse until eventually it'll work, then today just now I went out there to drive it around the block and cranked it and it started shaking violently and I waited til it sounded good and I tried to go but it didn't even lunge forward like usual just sat there, just nothing, seemed like I didn't crank it but from sound I did. Then I just again played around with it but longer than usual and it eventually worked again after a couple tries to go and drove just fine like usual, I always only have problems with the start up, I'm having a hard time diagnosing the problem I have looked up things about "system too lean" and it's a number of things that could possibly be wrong.