I did a search on this but I didn't really find a person with the same issue so please excuse me if I missed a thread about this. Anyway, I have a 08 G37S Coupe and 2 weeks ago I had my berk hfcs finally installed and paired with my already existing stillen cbe. After driving the car a day or two my SES light came on and my car would idle at about 1100 rpms which is annoying. I then just thought my car had a hiccup adjusting to the newly installed hfcs so I drove to a local Autozone and had the ***P0300 random misfire*** code erased but after about another day at a cold start up the SES light came back on. Also I notice when I drive at any speed and I do mean any, I hear a hissing sound coming from the passenger side and I dont notice it coming from the driver side. It almost sound like air escaping from somewhere. I've had berks hfc on my previously owned 06 G35 coupe and I had none of these issues and I know about the rasp they make and this is not rasp. A few days after...the second SES light. Then went through the procedure of resetting my ecu and that cleared the light for about a day and once again its on again and its the same P0300 code.

Has anyone had the same issue or can give me some advise as to what may be going on? Prior to the Berk HFC install, I had absolutely no issues at all. Does anyone think it may be a vacuum leak? Im leaning towards a leak because I hear the hissing sound but any help would be greatly appreciated guys...Thanks.

 

Check that everything was installed properly. Sounds like a leak.

 

It certainly sounds like a leak. If possible listen to it from underneath while it's on a lift.

 

I dont think an "exhaust leak" would be a misfire codes, intake leak would but not exhaust

Possible causes

- Faulty spark plug (s)
- Faulty ignition coil (s)
- Ignition coils harness is open or shorted
- Ignition coils poor electrical connection
- Clogged or faulty fuel injectors
- Injectors harness is open or shorted
- Injectors poor electrical connection
- Improper spark plugs
- Insufficient cylinders compression
- Incorrect fuel pressure
- Intake air leak
- Mass Air Flow (MAF) sensor faulty

 

Check out this thread ... looks like couple of them had this code and it was fixed by the dealership

https://www.myg37.com/forums/g37-sed...ler-twice.html

https://www.myg37.com/forums/g37-cou...ve-of-god.html

Your car's still under warranty? It might have nothing to do with your Berks
Did you recently install an intake? It could be broken plug on the MAF sensor as that will throw this "MISFIRE" code.

 

Thanks for the input guys(: I do have stillen gen2 intakes but those been installed for at least 8 months now with no issues and I no longer have warranty. Well I still have the powertrain warranty not the manufacturer warranty. I'm taking it to get it looked at today, hope it's not too bad.

 

Hope it's nothing major, which am sure it won't be ... CEL i know scare the **** out of you but it's not always that alarming until and unless it's an Audi where the "Engine Malfunction" rapidly starts blinking and you have to stop the car and get it towed. Hope that never happens on my wife's A6. Scary !!

 

Ok, the results as of right now is there was two loose bolts on the passenger side cats where is connects to the headers. They were all tightened up and the driver side was checked as well. No more air escaping sound and the SES went off on its own. Hopefully that was the only problem and its solved now. We will see after a few drive cycles :-/

 

phew!

bet that was a load off.

glad it wasn't something major.

 

Ok, Got the G back and I have been driving around...still no SES light after several cold starts. On the other hand, the hiss is still there during acceleration and deceleration. I can hear it as soon as I begin to move. I especially notice it coming from the passenger side. Could it be a faulty hfc or is this normal? Will the sound eventually go away maybe?? Someone please help?...its driving me crazy LOL. This is making me want to sell them.

 

Oh yea actually, I did get a stud on the front passenger side replaced as well recently that had broke off. Doesn't this car have some kinda dust shield in the front? Maybe thats rubbing and making the noise???

 

I found the problem. Went outside just now and took the wheel off...the dust shield was rubbing against the back of rotor smh. Took a screw driver and pried it away from the rotor and now no noise at all. Turns out the hiss I was hearing wasn't from the cats after all it was really the grinding of the shield against the rotor. Whew...Im so glad it was that and not the cats because I was about to put those cats for sale LOL (:

 

NiCce always good to know its a easy fix!

 

I had a simialar issue with my TPs and come to find out since there wasnt a gasket between the TPs and manifiold I had a leak. I kept throwing a O2 sensor code. The dealer ended up finding a company that made gaskets to go in there and Ive never had another problem.