Cold air filter is only after market done..

ok so i got 2 issues 1) p0304 cylinder 4 misfire>done plugs NGKs oem called for, new coil boot swap coil swap injector< no luck at all

2) vacuum leak its a hiss noise from back side of motor and can be heard by the fire wall, i turn my steering wheel it goes away and it idles a lot better

any tip or help will be appreciated

 

Problem one might be a bad fuel injector harness or coil pack harness. Take a continuity tester and go after the words in both harnesses, if they check out let me know and we'll go from there.

Problem two might your brake booster hose leaking? Can you take some pictures of where you think the leak is coming from? It might help you to get a can of carb and choke cleaner, or non chlorinated brake cleaner and spray some of the vacuum lines back there. If it revs up or Biggs out after you spray a section of line that's your leak. Be conscious of what you're spraying however, both cleaners are aerosol based and combustibles, I wouldn't recommend spraying it on something extremely hot like you're exhaust...lol

 

If your problem is a vacuum leak, then you need to do a "smoke test". A smoke test will show where the vacuum leak is coming from. Take it to a shop and they can do a smoke test to pin point the leak. Going to a shop for a vacuum leak it the most affective the thing to do. They have a machine that will detect any and all vacuum leaks.

Or you can do a redneck version of a vacuum test and do it yourself by using a cigar and piece of hose. Youtube vacuum leak cigar and look for videos. It's not as affective as going to a shop but it will save you a little money.

DYI Redneck smoke test: (Youtube has tons of videos)
#1:Get yourself a big fat cigar at a gas station.
#2Put a latex glove over the throttle body and secure it with some rubber bands or zip ties. (You will need to remove the big hose that connects to the throttle body)
#3Go to an auto parts store and get a 5 foot piece of hose (make sure its the same diameter as the hose you blow the smoke through) Connect the hose to a vacuum port (I connected the hose to a port that that connects into the throttle body manifold)
#4: Light up the cigar and blow. You'll see the latex glove expand (make sure its secure), The expanding glove will ensure that you have smoke pressure going into the intake manifold.

The smoke will come out where the vacuum leak is at. Get yourself a good flash light and a head lamp so you can clearly see any leaks.