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So, the throttle body has a single flap in it which metered air flows past, into the intake manifold.......once the air gets past that throttle body flap, it passes into the intake manifold where it then passes through 6 individual flaps. These flaps are part of the variable length intake manifold runner design. If the #4 intake runner flap is faulty, this could account for your P0304 code. Maybe the flap has become loose on the actuator shaft........once the intake air gets past the 6 manifold (variable length) flaps, it has to (once again) pass thru 6 individual flaps within the lower intake manifold plenum......if the #4 flap in the lower plenum is faulty, maybe it's causing the P0304 code.
Well, walnut blasted the valves (they were terrible), changed plugs and coils this weekend. Still won't start and still has p0304 code. The code comes back immediately even before trying to restart the car. I hear the pump on so think it's getting fuel. Wiring issue? Any other ideas?
If you get the car to start use the injector cleaner, the nemes is is Abro. Like I said, I drove 4 hours back and forth with no problem the first few days when I used the injector cleaner. I got the code, but after two weeks it was gone.
Well, nothing has worked. Replaced injectors and still no start and p0304 code. Code stays even after clearing with scanner without even trying to restart car.
Thinking wiring issue or ECU at this point. It is a repossessed car with what looks like a new key. Will it even try to crank if key not assigned to ECU?
I have been having this same issue. Cylinder 4 misfire, car would run great until it was under a load and would go into limp mode and kept throwing cylinder 4 misfire code. Haven’t been able to find any solutions through research. What I had found out on my end is I took the intake off and looked inside each intake port as I turned the engine over. I was looking to ensure all the valves were opening and closing. One of the valves on cylinder 4 was not opening. I then took the drivers side valve cover off and I had a broken rocker for that valve that wasn’t opening.
Finally had time and replaced rocker arm with a new shim and issue has been fixed. I did not have to remove cam or anything, I was able to compress the valve spring enough to slip the rocker arm into place. If this is someone’s issue make sure the valve shim is still in place (mine was missing) so fingers crossed no issues down the road.
12-28-22, 08:48 PM
