Okay, let me try to remember all of these problems:
A few weeks ago while driving, my car started to sputter and then as I started to feather the gas it just died. It made a loud groaning noise right as it quit. I let it sit for a few minutes and it would re-start, but then die quickly. I had no CEL. Then I replaced the fuel filter and it sat for a few weeks. I took it out the other day and at first it was fine. I drove 15 miles to work and it seemed to miss like 2 times on the highway when I was giving it a little more gas. Still no CEL. Then i was sitting on a hill at a light, and when I went to go, the car almost stalled, so I put the cluch in and gave it more gas and tried to go and it almost stalled again. Then on the way home, it kept "missing" for the entire ride. Also, when I stop, the idle is all over the place. I can't tell if it is electrical or fuel. Please help.

 

i have no idea what the groan could be.

start with the basics.

check to see if you are getting spark, fuel, etc.

 

How should I do that? I mean, I must be getting some kind of spark and some fuel, cause it didn't die on the way even though it was missing a lot.

 

Sorry about your troubles. Have you checked and verified if the MAP, TP, CKP, and other sensors are working properly? A faulty MAP sensor can cause stalling and erratic idle problems, while a faulty TP sensor may cause a "false misfire" sensation while driving. A faulty MAP sensor signal will NOT necessarily cause the MIL to come on (I know this first hand!). If that's the case then it's intermittent here. I'm assuming you've already verified that your ignition system (cap, rotor, wires, plugs, etc.) is fine and that the fuel pressure is within spec. The easiest way to verify your sensor inputs is with a "scan tool" that you can buy at a parts store.
And lastly, don't forget that wiring problems themselves (intermittent shorting/grounding/opening) can cause the problems you're describing. I hope some of this helps, and good luck in your diagnosis. I am clueless about the "groan" since I haven't heard it.

P.S. Is your engine JDM or USDM (just curious)

 

you havent by chance wired in a fuel pump cutoff? This sounds similar to what my car was doing when my switch went on the fritz.

 

When I paid for the engine swap, it was supposed to be a JDM motor. And although the valve cover seems to be, I have a friend who is very familiar with the jap spec B16A motors, and he said the code doesn't match. That was just the beginning of my toubles. It has been almost 4 years since, and everything is screwed up. I used to put 30k miles a year on my car, and in the 4 yrs since, I have only put 50k total on it. It sucks. Not to mention that they charged me 6500 bucks for the work which took 2 months even though it was supposed to take a week. I should have done it myself, but I didn't want my car tied up for more than a week. Before that, all the work I ever did to the car was done by myself. I guess I will know better next time....

 

what is the engine code on the block?

 

I will let you know tomorrow. I brought the car to my friend's shop yesterday, and will hopefully have it back today. Maybe I will put up some pics so you can see how messed up everything is.

 

if it has a fifth digit, chances are its not jdm.