Ok I have searched a lot about P0300 and have read about all the issues that cause it. I recently had gsc s3 cams installed and prior to that I was running hks 272, I know have the dam p0300 code. I know I have seen a lot of people saying that gsc cams can cause this along with twin disc clutches . I run a hks twin disc and never had this issue with my hks cams. The first time it happened I swapped out the plugs as they had some miles on them, this fixed the problem for about 500 miles but know its doing it again. I'm running NGK BR8ES gapped to .024, should I gap them tighter? I run a spark tech non cdi cop . Its quite annoying because the car breaks up real bad and I noticed when it breaks up my AFR goes to 10.0, and as far as I know it might even be richer then that. So should I have p0300 disabled? I guess I try new plugs again, but that just seems to work for a little bit. Any other suggestions ,cam sensor etc.?

 

What year is your Evo and how many miles do you have on it?

 

2005 30,000 miles

 

I got this with my cams after install.Turned it off in Tephra.

 

I just threw some new plugs in and it helped a lot but it does happen still randomly for a split second. I don't run Tephra, my ecu is flashed can I still get it disabled by my tuner?When I get this sputter are the gsc cams so noisy that the ecu is thinking its knock? When this is disabled would it eliminate the sputtering condition and will the ecu still be able to detect knock? When I pulled my plugs they seemed to look ok and not fouled, they only have 500 miles on them.

 

I don't run Tephra and I turned it off and yes it still detects knock.

 

Thanks for the info. I'm going to bring it back to my tuner to look the car over to rule out that its not mechanical . I installed new plugs BR8ES gapped @ .020 and my sparktech cop only has about 3000 miles on it. Has anyone heard of the spark tech cop having issues? I will look into disabling p0300, if the condition still persists after it disable what code would it throw then?

 

P0300 will be a memory. If you have a tuner car you should have a AF gauge and a boost gauge. Also, I recommend the Tephra flash on knock. Those things should keep you out of trouble. You'll know what is causing the miss when you find it. It may well be bogus.

 

This sputter that you are reffering to is it like a hesitation that occurs when you are trying to accelerate? And if so does it happen in all gears or only in 5th gear under part throttle.

 

I've been fighting this code as well. I have had one cam sensor replaced. Looked like everything was fine but it came back again, Going to replace the other cam sensor and hope that cures it.

 

I do have only 2 gauges so I went with a aem wb af gauge and boost gauge. As far as the miss I hope its something simple, but probably wont be

 

I would say as I have heard others say that it sounds more like a machine gun. The car just totally stops accelerating for a second or two. I have only experienced this going WOT though, it seems to be ok just cruising. Its also happens more at the top of 2nd gear or mid 3 rd gear. The thing I find odd though is when I throw some fresh plugs in there it helps a lot but for about 500 miles and then its back again. Could it just be in the tune and the new plugs mask the issue for a little bit? As long as my wide band is working right its not a lack of fuel because I'm seeing 10.0 afr and thats as low as it reads,( this is when its acting up). Maybe its too rich, the car was tuned in much cooler weather and now it 90+ degrees here in CT the last few days.

 

Check this out and see if any of this applies to what you are going thru: https://www.evolutionm.net/forums/ev...8-stutter.html

 

No the car runs great at part throttle and cruising its just when I go WOT 2-3 gear, don't know about 4 or 5 because it was so bad I didn't want to try it in the higher gears. So far with new plugs its fine but odd sometimes, for instance if I go WOT in 1st gear it pauses for a split second after I shift into 2nd and get to about 6000 rpm. It will then repeat sometimes from 2nd to 3rd on a shift also but if I'm already in 3rd gear and go WOT 50-90 mph it pulls like a champ with no hiccups. It seems as the plugs get a few hundred miles it becomes more frequent and sputters worse. I guess I'll have my tuner look into it.

 

Hmmmm maybe your MAF is dirty, or your 02 is on its way out. Def check with your tuner though bro.