Hey all,

I just installed GSC 272/272 cams with no cam gears or flash yet. I drove the car for a couple miles (around 20-30 miles) and just got the P0300 misfire code for the first time (never got it before). Anyone have any ideas on what it could be?

I searched and read that getting the dealership reflash to get rid of the P0300 would basically make my ecu un-flasheable by any of the tuners out there.

I'm thinking maybe because when I put the spark plug covers back on my car, I originally put them in the wrong order and when I turned on my car it was acting all weird (major backfire and engine shaking hard). I fixed that, but maybe I messed something up in the process.

Any ideas you guys/gals have would be great! Thanks!

P.S. My current mods are 3" DP, 3" HF Cat, 3" CB, Buschur Intake, Greddy BOV

 

i got the same thing the other day p0300 (multiple cylinder misfire). i had my 272s for a while and i just got flashed a week ago and i still got it, so im not sure on whats causing it. my thoughts were maybe the gap on the spark plugs need to be differant. im not sure thats just my guess and question also?

 

I put in new cams, turbo and manifold last month and then I got it custom tuned about 2 weeks ago and after 100 miles i got the p0300 code. I have 11k miles on my car and before this tune I had it flashed 3 times and never had a problem. I believe it has something to do with the flash that was done. 11k miles and 3 flashes w/mods and NO P0300. 4th flash w/cams,turbo and maniflold and code now comes all the time, somethings not right.

 

This code does not hurt performance at all. It is very common to get this code after cam install. I installed my cams and drove the car about 20 miles with no code at all. After my flash I get the code from time to time (every once in awhile it goes out but is on more than its off). I think its due to when they reflash the ECU they advance the timing at idle for cammed cars to help them idle better. This timing advance is what is causing the engine light IMO.

I really wouldnt worry about it but if it bothers you that much the dealer has a reflash that will fix this. Keep in mind if you have a flash already and you take it to the dealer you will lose your current flash. After visiting the dealer you can send your ECU back off to have it flashed again. Hope this helps.

 

ok so is there really a miss fire or is the flash making this code come up? just making sure im not running it hard and getting this code for a reason.

 

More important is who flashed the car, and was it custom or a mail in flash. I'm seeing the P0300 code becoming a trend with a certain tuner's flashes. I went through two different tuner's flashes on the HKS 272/272s, with no cam gears, and the car ran like a charm. Now, on the third tuner's flash... well, I've made it four days max without the code.

 

I'm running on the Vishnu mail-in flash but I got it before I put the cams in. I reset the battery and the cel went away for a little bit but still came back on. I'm thinking maybe if I get reflashed for the cams it will go away or either is it possible my timing belt is off during installation? Like would that cause a P0300 cel? Thanks all for all the input.

 

I noticed it samething... sounds like aids

bryan

 

I get it too ever since I switched from 264-272 to 280s. I bought one of those actron OBDII scanners and erase that annoying P0300 as needed. It cost me $145 but now I can erase codes at any time given. Good luck

 

what gap are yall running on your Spark Plugs? I am not getting any codes and ive been on GSC 272's for about 400miles. I dont have flash and im on stock cam gears. Im not tuned either.

 

when did the cel turn on, while cruising or under acceleration? if it happened at idle that's not a big deal

 

The first the cel came on it was at idle.the 2nd time i dont remember when it came on..it was just suddenly there when i looked. I'll prolly take a look at my spark plugs to make sure they are ok since as i said above i messed up when putting the covers back on.

 

A strange question, but I thought I would ask. Who here gets the misfire code when it is cold outside? Let's say under 70 degrees.

 

i don't have cams, and mine gets that code sometimes, mainly on road trips. one of my friends talked to a tech at the local Mitsu dealer here and he said that some of the evo's have this problem and he reflashed my friends ecu so it doesn't come on anymore

 

mine throws the code mostly when crusing but after i push the car. i have a mail-in dynoflash. to day while driving i had the ses light on and when i shut the car off and turned it back on after a half an hour it was gone! now thats some crazy shiet. im running stock plugs with 17,000 miles on them 272s with stock gears, apexi intake, helix piping, greddy type s, hks dp, perrin test pipe, and hks ti exhaust. i have to check the plugs to make sure everything is running right. should the gap be differant then stock for the mods i do have? and whats stock gap?