Ok so before I start I have looked everywhere for days and couldn't find any answers. I found similar but nothing like my problem.
So I was driving under normal conditions in the city on a straight road when my car backfired and revved up a few times. And the shitty idle problem at stops. I got home fine no problems, throttle was responsive, and nothing seemed wrong. The next morning I got into car and drove from point A to B fine. As I left, the car wouldn't start. It cranked and cranked till I gave it gas. Once started the RPMs at idle were normal as well as throttle repose. So I drove off. A few min latter when I shifted into third gear it started sputtering and revving up and down. I shifted to 4th no problems there. I pulled over and the car died. Same issue with starting again but this time as soon as I moved the stick into first it sputtered and revved erratically till it died. So I put it into second hot on the clutch and took off and was fine till I hit third again. I got home. The car dies as soon as I put it in gear and now at starts I have to rev it high till it idles normal, but min later it sputters and dies.
No clanking or odd noises other then exhaust. I cleaned the MAF and throttle body it did nothing.
I hope it's just the fuel pump or injectors. I got a barometric pressure code which wouldn't impair my driving ability from my knowledge?.. And because I drove it home like that I got p0300 random misfire.
Fuel filter is new along with fuel lines. Oil is new. Spark plugs are 10k old. Half a tank. Only mods as of now is zzp CAI and cat-back. Any ideas? Because I don't want to spend a fortune at dealer if I can do it.

Thank you

 

Ummmm yeah, the barometric pressure sensor would explain the whole thing! Check the reading from it, if it does not check out with your actual barometric pressure where you live, then change it out.

 

It would also explain your random misfire.

 

Ha thanks for both replays on both threads. I'll check it out today.

 

We're exactly is it located?