So I've been doing a little bit of experiencing... since middle of summer last year, I've been on e85. Everything has been great and I have no complaints other than sometimes having trouble with cold starts (which I've been too busy to address). I used to have the infamous P0300 code when I was on pump and being on e85, it never showed up once. A couple weeks ago, I went back to pump because I had a short road trip and did not have access to e85. Well, during that trip the code came back up.... now, 2 tank of e85 later. No code again!
This leads me to believe that the code, in my case is directly related to running 91. I know it can be also result of my tune but I have done a lot of logging and tweaking to fix this issue so I tend think that my map is ok.

So anyways, I thought I throw this out there and see if someone is also experiencing what I have been.

 

I have run on 91 and 91 + Meth and never had the P0300 code...So the code implies that you have a misfire issue, which if solved by adding e85 (and different tune) would lead me to believe there is either an oxygen sensor problem or an injector problem....Both can be tested to determine the route cause...

 

You also don't have a 2003 P0300 monster Evo.

 

Beat me to it

 

The PO300 code isnt ALL bad...It just your evo being nice, it lights your cabin up at night so you dont lose things in the dark. Think of it as a night light

 

hahahahahaha

I put my aem wideband on the steering column just right so it conveniently blocks the light, lol

 

Ditto, but its my boost gauge lol

 

Brian -- When are you going to help me convert my 06 into a monster ....

 

PO300 code = Random Multiple Misfire Code

Which ROM are you using: 94170008, 94170014, or 94170015? I'm very curious.

I never had the PO300 code when running 91 octane; then I moved to E-85 and simultaneously upgraded successfully from the '08 ROM to the '14 ROM. All was good.

However, when I try to upgrade from the '14 to the '15 ROM I start getting the PO300 code. Often. All of this on E-85. The PO300 hits so often that I promptly go back to the '14 ROM. Never have had a PO300 on the '14 ROM.

 

I actually tuning with racer tuner from Cobb. I have the ecuflash program but I have to buy the cable still.

 

You mean the AccessPORT device? Using the AccessTUNER Pro software?

 

Yes, I'm using the AP but with race tuner. Its the end user version of Pro tuner.

I mean race tuner not racer tuner from the last post so maybe that cause some confusion.