As I was driving the car made what I can only describe as a coughing sound out of the exhaust in the engine and shut off completely while all the electronics remained on. I had it towed to my house and now it cranks and sounds like it's close to starting but it does not. Sometimes after about 3 seconds of trying to start it a very low muffled Bang will happen. I have checked the spark plugs and ignition coil and they all register fine on the multimeter. I've also checked the fuel pressure and I can hear the fuel pump start when I turn the key. I've tried using starting fluid, but that doesn't help either. I've never had to go this deep into trying to get a car to start So how would I check the vacuum seals?

​​​​​​ also because of an oil leak the car was constantly low on oil and at times had none when I checked (girlfriends car, don't blame me I told her about the importance of it)

​​​​ edit colon It gave an error code of P0340 which is the camshaft sensor. I checked it out in the entire area was covered in old oil and I took it off and there was oil completely covering all of the parts. I'll test it and maybe just straight-up replace it.

 

Maybe snapped or stripped the timing belt.