P0304 code AGAIN!

[asiahispanico]

Hey everybody i have searched for this topic over and over and nobody has had it happen to them once it was resolved, well i changed my egr valve about two weeks ago because before then it had read a p0304 egr malfunction, the car would act funny and misfire and the rpm needle would dance around my tach im talking literally bouncing up and down upWTF and down until it misfire and POPPED then it would drive normal again , until i let off the throttle then it happened again. Well its been two weeks the car has started running like crap again, i put in new NGK BPR6es and NGK spark plug wires, the plugs look good alil on the rich side but better then lean . I know i have a vacuum leak somewhere behind or within the intake manifold i checked all vacuum lines but i can still hear a distinct hiss noise so i know hteres a vacuum leak i just cant pinpoint it. i am going to take it to a mechanic tomorrow. I cleaned out the throttle body yesterday, put in new gaskets and all, thats when i noticed the vacuum leak, its a noticable hiss and the car outright wants to die while warming up. Here is what my mods are for those of you that would think this would affect me running like this:

6 bolt swap (rebuilt block (JE pistons 8.5:1, Eagle ROds, ACL trimetal race rod and main bearings, and rebuilt 6 bolt head with slowboy racing valvetrain)

slowboy big 16g and ported 2g exhaust manifold and o2 housing

hahn racecraft upper and lower intercooler piping and front mount intercooler

autometer boost gauge and af ratio gauge (not working)

apexi safc and turbo timer

turbo xs bov (recirculated)


i know i need dsmlink so please cut me some slack on that one, but oddly i have not had the random misfire problem but only a handful of times and ive had this car since about april! (knocks on wood)

im sorry for the ridiculously long post but im seriously stumped i really dont know what else to do any help or criticism as this point is appreciated.

 

[olmytsi]

P0304 is cylinder number 4 misfire, not egr malfunction.

 

[beating4g63s]

you have a misfire on cyclinder 4 swap one by one your spark plugs, wires, injectors, for antoher on either 1,2,3 if the cel goes from p0304 to p030x then whatever it was you last swapped then you need a new one it also could be the coil or wiring harness or ecu.

 

[asiahispanico]

interesting i had it scanned at advanced auto parts and the print said p0304 egr flow malfunction, hmmm interesting im taking it to a mechanic tomorrow so well see whats up with it, thanks you guys

 

[olmytsi]

Those advance auto people suck , invest in a logger for yourself .

Or, whenever they give you the code, come on the forums and type the number in the search tab and you will get ALL the info you need. That's what i used to do before i had a logger.

 

[asiahispanico]

well took it to the mechanic today, they told me the hissing is the air bouncing off of the intake manifold, i dont know i never heard that noise before i cleaned the throttle body. Im investing in a replacement 2g throttle body, i think the air leak is coming from the area where the throttle cable is connected to the throttle body, i remember reading on here somewhere about the o-rings or something of that nature. I do know that the car runs awesome, but my boost is spiking where its usually at 12 its sitting at 20 and its blowing vacuum lines off like crazy. I appreciate the help though, thanks everybody

 

[shadowdrag]

Is the hiss from the intake mani sound like someone honda civic with a big cold air intake? Because mine sounds like that for a while now and I don't know whats going on. I try everything, o-rings, TB shaft o-rings, new gaskets, new vacuum lines, and a rebuilt TB, its still the same.

How is the code now? Is it still on or how did you come about to fix it.

 

[olmytsi]

well took it to the mechanic today, they told me the hissing is the air bouncing off of the intake manifold, i dont know i never heard that noise before i cleaned the throttle body. Im investing in a replacement 2g throttle body, i think the air leak is coming from the area where the throttle cable is connected to the throttle body, i remember reading on here somewhere about the o-rings or something of that nature. I do know that the car runs awesome, but my boost is spiking where its usually at 12 its sitting at 20 and its blowing vacuum lines off like crazy. I appreciate the help though, thanks everybody

Do a boost leak test!!!

20psi on stock fuel could damage stuff so hopefully you have at least a fuel pump. If not dont floor it til you lower the boost.

 

[asiahispanico]

hey guys by the way th\
e code was p0403 not p0304, BIG mistake . Well the hissing '/
coming from the intake mani and throttle body area doesnt seem to be a boost leak, Im still going to do the test but the car idles perfect now, even at 20lbs of boost. My fuel pump is upgraded, the dealer told me that was one of the mods they just got done doing on it, it has i believe a walbro i want to say 190 on it, but would it be able to run at 20 lbs on a big 16g? The car runs oddly normal and idles normal. Im holding at around 19-22inches of vacuum at idle, it boosts at around 2600 rpm (with stock exhaust, yes i know I NEED TO UPGRADE) when it does boost...it GOES. Im driving it moderately until i can figure out the boost spike issue. I believe its my boost controller though, the turbo xs DSMBC doesnt seem to work anymore, at low it boosts 20, at high same thing. I checked my plugs, heres the great part, STILL RICH

 

[Raph]

Is the hiss from the intake mani sound like someone honda civic with a big cold air intake? Because mine sounds like that for a while now and I don't know whats going on. I try everything, o-rings, TB shaft o-rings, new gaskets, new vacuum lines, and a rebuilt TB, its still the same.

How is the code now? Is it still on or how did you come about to fix it.

I had that hissing noise too.. a) My boost guage still leaks (from the guage face itself)
b) The vacuum line going to the egr controll solenoid had a tiny hole in it .. right about halfway to the egr valve.. causing a hissing noise around the intake manifold