So I have this up on another forum but would love some input from the gurus over here.
Currently I'm on a E85 tune (for about a year now), but about a month ago I started getting this P0301 code every time I cold start the car. The code pops up after a minute or two of idling.

So here's what I tried so far and I'm still getting this error....

Replaced:

Front O2 sensor
spark plugs (NGK Iridium)
coils\wires

Moved the injectors around (swapped 1 with 3)
added fuel at cold start
checked for boost leaks

But for some reason I still get this stupid error when starting the car after it's been sitting all day or over night. Within the first 3 minutes of starting the car, it's there. I'm seriously considering throwing the stock flash on there and running pump gas to see if it clears up. Not sure what else it could be???
When cruising or WOT there is no issues at all, car hit's AFR's exactly where they should be, and drives great. But at idle it pops and misses intermittently, and the AFR's tend to wander a bit but always return to stoich within about 10 seconds after letting off the gas.
Any chance it could be the EGR or idle switch or some other weird sensor? Also, someone mentioned turning off the O2 feedback at idle - does anyone have instructions or more info on doing this? Where are the settings for this? Also, where do I turn off the misfire code? I have a Tactrix cable now so I can poke around and do this myself with a little help.

Thanks everyone

BTW, mods are in my signature, this is for a 2006 Evo IX 5 speed.

 

Turn it off in the tune or have it turned off.

 

Whats the idle timing look like?? Too far advanced and you'll throw misfire codes at idle.

Many tuners will advance it out to help with idling using aftermarket cams but advancing it out too far causes misfire issues

 

Post #3 if you want to get to the root of it. Post #2 if you don't care.

 

I'd really like to figure out the issue.. I'll check on the timing at idle. I think it fluctuates between 12 and 17 degrees.

 

If so there is your problem my car wouldn't take that at idle without throwing a misfire code usually a P0300 but any cyl misfire can be thrown

 

So, which tables do I adjust to lower the timing at idle? Sorry, just got my tactrix cable so I'm still learning to use the Evo software (way different from DSMLINK)!!

 

High Octane Ignition map at idle rpm/load cells.

 

for the hell of it, check your vacuum lines going from throttle body and egr valve to the egr solenoid. Also make sure one of the plastic nipples on the egr solenoid isnt cracked or broken.