anyone have any ideas why my car is throwing a P0300(random misfire) code?? mods are turbo xs 3" TBE,evoscan flash,forge bov,ams fmic,780 cc injector clinic injectors(dont like'em),snow performance meth,blitz sbc-id(maxed out),stock turbo,hks 280's,samco ic hose kit,magnacor wires(dont like),quartermaster twin disc(sucks). my shop is saying its the chattering of the cllutch which is throwing the code. never had the prob until the last products i had installed which were the CLUTCH and injectors. now my cel keeps comming on with the misfire code. swapped ecu out for a 9 ecu and it seemed like it helped for the first 80 miles then wham a cel misfire. i had a hks ssqv bov on and swapped that back to my forge and my cel went off for about a week and a half and then when i was driven with my friend in it and just happend to mention the cel prob that was fixed by swapping my bov's, WHAM, the cel light came on. then when and swapped out the ecu and still the same thing. i can be on the highway with my rpm around 3000 and then it just starts sputtering and my afr's go lean and my egts go DOWN , figure that one out. i have to take my foot off the gas and then get back on it for it to clear up. any suggestions would help out, thanks.

 

Whoa, why in the WORLD did you swap a IX ECU onto your 03??? The IX ECU has completely different programming with things such as MIVEC and ACD. You don't just change your ECU when you get a CEL, and you sure as hell don't change to an ECU from a year that is nothing like yours!

There are a lot of possible causes for the P0300. Did you search through all the discussions and fixes? It's the most common code on the Evo by far and sometimes it just doesn't go away...

 

I am assuming you had your car re-flashed when you had the injectors installed. To me it sounds like bad tuning.

 

It would be impossible for him to swap ECUs. E8 has a 4 plug ECU and the E9 has a 3 plug ECU. They are completely different and can not be swapped from one car to the other.

 

That is true, but that's what he claimed. I guess it could be done with a custom harness or some tricky splicing, but it's more likely that he doesn't realize he just swapped in another VIII ECU.

 

maybe it is a 8, thought it got swapped out to a 9. but i didnt have a prob until i put the clutch in and injectors. would raising my timing do that? i think its at like 10% but i can only get around 6% out of it on a road tune. my afr's are around 12.5-13.5 at wot and 30-32psi with 0 knock. i thought it might be the timing but they seem to think its the clutch chattering.

 

my shop just swapped the ecu and took the flash from the old and sent it to the new one. no cutting wires or splicing

 

The issue is most likely in the flash. Sounds like it was not tuned right after the injector install.

 

12.5-13.5 AFRs??? You can't be serious...

 

whats wrong with those afr's????????

 

its not lean and its not rich and no knock @ 30psi on 93

 

oh yea, not that it really matters but i have a k&n intake and running denso iridiums. maybe it is the clutch, god, not another 1700 down the drain

 

another ?, would an aem ems solve the prob???? i heard of people having probs starting there cars in the winter with the aem ems, i just cant afford to have this happen as my car is a daily driver. i heard that there is a ssafety function which dont allow the fuel pump to turn on.

 

Hey, man, you don't have to reply to yourself over and over. Just edit one post and keep adding questions.

As for this question:

I cannot believe you are asking what's wrong with those AFRs. That is EXTREMELY LEAN. You're saying you're not knocking, but I don't believe it, because you thought you had a IX ECU and think you are running 12.5-13.5 AFRs without knock. Neither of those is true.

 

A good flash would most likely solve your issue.

The AEM will not solve your issue unless you have it properly tuned.

Most cold start issues with the AEM are due to poor tuning although cold start is hard to dial in when its not cold out.

There is no safety function that disables the fuel pump on the AEM unless you for some reason wanted one programmed in.