BlewByYouEvoVIII
04-02-2007, 09:27 PM
Ok here goes. The problem with the 03-05 Evo's throwing the P0300 code has been a mystery to myself and many otherse. Mitsubishi and many knowledgeable tuners dont seem to have a good fix for it. Mitsubishi has released several reflashes for our cars because of it, but in the end they claim that it is a faulty or worn input shaft. I did further research on this to find that to get the input shaft replaced it would be the cost of the input shaft plus 8.5 hours of labor. We are easily looking at over $1000 in repairs for something that quite possibly may not fix a major problem. Can you imagine spending over $1000 to fix a problem just to find out that on the way home your SES light came back on? Back on topic, I don't see a problem with the 03-05 input shaft. Speculation is that it makes an abnormal vibraton that somehow triggers the P0300 code. The P0300 code, for those of you who don't know is a Random/Multiple Misfire Code. How a faulty input shaft can trigger this code is beyond me. It never really made since to me how this could be the cause of the problem.
Upon further research on the cause and fixes for this, I found some pretty interesting stuff. Have you ever wondered why the more heavily modded cars seem to have an upgraded ignition system? Ever since I started having problems with the P0300, I assumed it was something related to ignition. However, none of the known fixes for this code are ignition related. The Evo8 ignition system only has 1 coil. So 1 coil is responsible for the load of 19PSI (stock). Well, what about when you tune the car and turn your boost up to say 24PSI? So this stock coil is responsible for one hell of a load.
Here is what I have found. When you start messing with the boost levels and raise it quite a bit over stock, the spark that your spark plugs cause can easily be blown out by the elevated boost level. This does not occur all the time, but is more likely to happen. In addition to this, it is quite possible for this to even happen to a stock Evo because of the weak ignition system. This is also the reason that it is recommended moderately modded Evo's upgrade to BR8EIX spark plugs, NOT BPR8ES plugs. You need to gap them at .24, not higher. This is supposed to help prevent misfiring. This however, does not fix the P0300 in most cases, although it is possible it may help.
So we found the problem, how do we fix it? I somehow stumbled across a few people talking about upgrading entire ignition systems. The HKS DLI II one seems to work just fine for most people. However, as any HKS product it is overpriced. In addition to this, there are reports of a few people having these entire systems blow out on them. Not a risk I want to take for a $500 unit. Sun Auto, a well known company in Japan, has an alternative. It is still an entire ignition upgrade, but it only costs around $300 and contains a fuse on it. The fuse is a nice safety net so if something should happen you dont blow the entire system. This system allows you to run higher levels of boost, or stock levels, without having the spark blow out on you. In addition to this, they have dyno tested this on a mustang dyno and picked up 8whp. The system not only adds hp and prevents spark blow out, but also helps your car to run smoother throughout the powerband and also runs alot smoother at idle. There are numerous reports of people who have bought these systems and have never seen a P0300 code ever again.
This explenation is quite a bit more logical than any other one I have heard of. In the next week or so I will be buying one of these systems and installing it on my car. It is not a 100% guarantee as of now that this will infact solve my problem. However, I believe it will, if nothing else I should pick up some better HP numbers and help my car to run smoother. I will keep everyone posted on my progress with this. This path just seems to make sense as far as a P0300 fix. I feel somewhat encouraged that the other customers of this product are no longer throwing a P0300.
P.S. Sorry this writeup is so long, I thought it would be useful for everyone who experiences this problem to have some background info on it.
Upon further research on the cause and fixes for this, I found some pretty interesting stuff. Have you ever wondered why the more heavily modded cars seem to have an upgraded ignition system? Ever since I started having problems with the P0300, I assumed it was something related to ignition. However, none of the known fixes for this code are ignition related. The Evo8 ignition system only has 1 coil. So 1 coil is responsible for the load of 19PSI (stock). Well, what about when you tune the car and turn your boost up to say 24PSI? So this stock coil is responsible for one hell of a load.
Here is what I have found. When you start messing with the boost levels and raise it quite a bit over stock, the spark that your spark plugs cause can easily be blown out by the elevated boost level. This does not occur all the time, but is more likely to happen. In addition to this, it is quite possible for this to even happen to a stock Evo because of the weak ignition system. This is also the reason that it is recommended moderately modded Evo's upgrade to BR8EIX spark plugs, NOT BPR8ES plugs. You need to gap them at .24, not higher. This is supposed to help prevent misfiring. This however, does not fix the P0300 in most cases, although it is possible it may help.
So we found the problem, how do we fix it? I somehow stumbled across a few people talking about upgrading entire ignition systems. The HKS DLI II one seems to work just fine for most people. However, as any HKS product it is overpriced. In addition to this, there are reports of a few people having these entire systems blow out on them. Not a risk I want to take for a $500 unit. Sun Auto, a well known company in Japan, has an alternative. It is still an entire ignition upgrade, but it only costs around $300 and contains a fuse on it. The fuse is a nice safety net so if something should happen you dont blow the entire system. This system allows you to run higher levels of boost, or stock levels, without having the spark blow out on you. In addition to this, they have dyno tested this on a mustang dyno and picked up 8whp. The system not only adds hp and prevents spark blow out, but also helps your car to run smoother throughout the powerband and also runs alot smoother at idle. There are numerous reports of people who have bought these systems and have never seen a P0300 code ever again.
This explenation is quite a bit more logical than any other one I have heard of. In the next week or so I will be buying one of these systems and installing it on my car. It is not a 100% guarantee as of now that this will infact solve my problem. However, I believe it will, if nothing else I should pick up some better HP numbers and help my car to run smoother. I will keep everyone posted on my progress with this. This path just seems to make sense as far as a P0300 fix. I feel somewhat encouraged that the other customers of this product are no longer throwing a P0300.
P.S. Sorry this writeup is so long, I thought it would be useful for everyone who experiences this problem to have some background info on it.