I'm currently tuning a 2.3l GT30 car with 280's and he has the same P300 issue ... I've updated to the 94170015 RPM as well as tried several combinations of reduced timing in the main map and the adv/ret map. I've also tried smoothing the timing transitions .. all to no avail.

This seems to happen more in higher gears at low RPM ... the recent one was at about 2200 in 5th. The recent changes I made seem to have helped in lower gears though.

Any thoughts? More of the same till 5th doesn't throw it either?

 

I've noticed it mostly gets thrown during 4th and 5th gear also, but I did have 1 time in 3rd gear that it came up also, but it was more of me holding part throttle around 3300-3500 and then the typical misfire burp. I would imagine though with a 2.3l that the off-boost timing area would be different from the 2.0l. I would like to note that I also have my "open loop load #2" map slightly lowered between 3000-4000rpm. I noticed it seemed to smooth some of the transition into boost in regards to fueling.
The only strange issue I have now is through 1st and 2nd gear...crossing from vacuum to boost will light up my cel knock light, but 3rd 4th and 5th won't do it. Time for more logging, guessing timing needs to be lowered in the low load areas more.

 

Has anyone defined this portion of the 96420008 ROM yet. I couldnt find it anywhere.

 

sorry for the newb question.
how do you update to 94170015? is it like cut and past of all the tables from current 94170008?

 

Yup and flash it in

 

im having this problem with my evo ix after i got cosworth m2 cams and meth installed. i also bought one step colder plugs from lancershop thinking it would fix the problem but it didnt