I got retuned and after a month sometimes under full boost the check engine light flashes. Only problem is that it doest stay on so I cant pull a code. I think also I have a rattling heatshield or rattling down pipe would the vibrations cause the cel? Why does it go off? Any ideas what it could be? I have had problems under cold starts too, I have had some stuttering until it gets to running temps. Any suggestions?

 

With the retune they uploaded the TephraMOD most likely, and it is signaling knock when you are boosting. The rattling could cause a false knock code, but it would have to be a pretty good vibration. Tighten them up and see if it fixes the problem. The ideas are either, the rattling or something else is causing false knock, or you your tune was a little too aggressive on the timing or boost, go and take a log of the event. Do you have a wideband to see the AFR? Are you still running 91 or 93 oct, not E85? I am asking because it is difficult to cold start on E85 sometimes. However, if you were running E85 or race gas, chances are you wouldn't e knocking if it was real knock... Take a log of the knock and see what it looks like, but if it is flashing it is usually 6+ counts (whatever your tuner set it to) but it is usually right around that number for DDs.

 

You are getting knock. I would contact your tuner. It isn't a code it is a patch as stated above.

 

+1 sounds like knocking from an aggressive tune

 

contact tuner as stated above

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