Up, any other ideas before I delete the p0300 code for good?

Also is there a list of known ROM ID's that suffer from this issue more than others?

Im running Tephra V7, dont remember the ID off the top of my head but I do know that I switched roms at the beginning of the summer to try and alleviate some throttle hang issues so I'm wondering if that could have something to do with it?

 

Bump

 

The P0300 happened to me on every rom I have used. I have tried the 94170008, 014, 015, and even the 9536.

If you are no longer getting a specific cylinder miss fire, then I would proceed and disable the P0300.

 

I used to get this all the time in my old evo. My '03 had the original factory transmission and there is a TSB out there for the 5th gear syncro assembly. The 5th gear assembly was found to throw harmonics in the same range as the knock sensor and you would get random knock right around 3k rpm.

I could throw that CEL at will by just using a light throttle in 5th gear at highway speeds. So, if you have never rebuilt your transmission, or if you have never opened it up, I would check out that area too.

I never heard of this on an '05, but I supposed with the higher millage cars this could happen over time.

good luck!

 

Thanks for the information. I remembered that that I had changed my rom so I thought it was worth mentioning.

Thanks for your input. I dont think it has any correlation to my transmission personally, well at least 5th gear. My car is still on the stock clutch and just hit 49,000 miles this past weekend. It almost always seems to happen right when I am entering a congested area and am putting along in 1st or 2nd gear. For example it happened last night on my road trip home. I drove 250 miles and it appeared right when I hit traffic before tolls in 1st gear. That was p0300 and I cleared it and it didnt come back for the rest of the trip.

This morning the code came on during my commute to work right at a stop light when I was slowly rolling up. I noticed it right when I stopped so I may have even been idling when it triggered. Ill check the code tonight to see what it is.

In summery since I cleaned my fuel injectors, I have thrown a code 3 times and so far they have all been a p0300. I want to make sure its only throwing that one and not a specific cylinder before I delete it all together.

Is there any other mechanical part of the car that I can check?

Thanks for all of your help!

 

I'm not sure that the P0300 OBD check is as helpful in finding real misfire issues as you might think. There was a period when my spark plug wiring was giving me issues, and I could easily feel misfires during WOT, but got no P0300 code.

 

I honestly have no idea how helpful it truly is. I am not an engineer or a certified mechanic so everything I have learned has been from reading on here as well as personal experiences with my car. With that being said, I still dont exactly understand and follow how the system triggers a misfire.

If the misfire is blatantly obvious, I would definitely pick up on it and know something isnt right. On the other hand, it is my understanding that a misfire will not always be obvious and is virtually impossible to detect by a human. It's that reason that I would prefer to have all the failsafes at my disposal.

 

I scanned the code again last night and it was another p0300. I am about ready to delete the code all together. I just want to wait and made sure it doesnt throw a specific cylinder code like it has in the past.

I will continue to update this thread. Thanks everyone for your input and please feel free to chime in if you have any other suggestions.

 

Threw the code this morning on my way to work. Its probably a p0300 again but like always I need to scan it to be sure.

The one thing I noticed is that I can now almost always predict when the code will be thrown. Right as I approach a section of traffic and am puttin along it'll throw the code. Usually this is <5mph and a lot of times I'm even stopped. This morning its came on the second my car came to a standstill right when I approached the traffic.

 

Can you post a pic of your timing map?

 

Sure, Ill update the thread later tonight.

If it were something to do with my timing why would this issue only arise now after I have had essentially the same map for the past couple of years?

 

No good reason I can think of. Just curious at this point. It interests me that it happens during idle. I had glazed over that the first time I read through. From what I recall and my personal experience, the code is thrown while cruising in 5th. I have seen a bunch of these threads.

I am going to take a look at the thread about disabling the code. See if anyone else talks about it being thrown at idle.

 

Thanks for your help. I assumed I could rule out my tune considering I never used to have this issue and my tune really hasnt changed much in the last couple of years, especially my 93 oct tune. It is definitely not occurring while cruising in 5th that's for sure. I have been doing a lot of highway driving recently and it will not trigger while cruising in 5th for a straight couple of hours but right when I hit a patch of traffic it'll come on.

It seems to come on right when my car is about to come to a stop where the idle is about to catch or sometimes even right after i stop and idle for a couple of seconds. Its strange because I think if I were to just turn on my car and let it idle for 15 minutes it wouldnt throw a code. It seems to happen in very light load situation where I'm slowing down. I really wish I had a log of the exact moment it happens, that would probably help. I just know if I'm logging it'll never throw the code

 

Bringing this thread back up. SOrry I meant to update it a couple of days ago but Ive been really busy.

mt057- I totally forgot to posxt my timing map but I'm not sure its necessary after I tell you the recent updates.

I am officially getting p0300 and sometimes a p0302. I think this means that I have an issue with an injector. If you recall I was getting a p0300 or p0303. A couple of weeeks ago I pulled the injectors and cleaned them. I then swapped their locations to see if the code would change cylinders which it has officially done.

Now I plan to pull the injector in cylinder two and clean it really thoroughly. I made a cleaner with a 9v gator clips and a temp switch to pulse the injectors along with some brake cleaner fitted to a syringe to simulate fuel pressure to clean them before. I will be extremely thorough this time and see if I can get it working myself. If the code comes back I will send my injectors into FIC and have them professionally clean them for me.

 

Hey I don't have many posts on here but with about 5 years dealing with alcohol and some in detail experience with E85, both are very quick to affect injector reliability if they are not being used very regularly. Anyway to get to the point cleaning them at home unless it is an injector that you can physically take apart and clean, your wasting your time it may get better but your deff going to end up sending them out. I know we all try to save time and money any time we can but its one of those things with alcohol/E85. sry to write a novel just trying to get some posts in and maybe help. Good Luck.