Mitsubishi Lancer Evolution Forum banner
1 - 20 of 21 Posts

·
Registered
Joined
·
52 Posts
Discussion Starter · #3 ·
Yes. Really.

The car is high compression, 2.2L, sleeved and step colder plugs. It is also the shop car. So if you think this is a problem, I am happy to debate it with you.

I am not looking to put a band aid on a customer car b/c the tune is off. I would think I would get the benefit of the doubt on this.

John
 

·
Registered
Joined
·
52 Posts
Discussion Starter · #6 ·
0 Knock counts

FIC 1100cc New Injectors, OHM consistent

The motor is running very nicely, just the code. I am pretty confident this is related to the 10:1CR, aggressive cam profile, HKS step colder, and dual Cosy springs.
 

·
Registered
Joined
·
6,693 Posts
A P0300 is a real code. If you have this code, you need to fix the cause. Your car is missing.

Releasing a disable would be stupid. That would be like making it so that you can't tell when you are low on gas.
 

·
[NEEvo President]
Joined
·
15,153 Posts
I would agree a P0300 is typically a 'real' code. However there are extenuating circumstances that would indicate otherwise. A vehicle with different comp ratio, fuel, cams, etc can cause a false reading.
Could explain how those things could lead to a false reading?
 

·
Registered
Joined
·
6,693 Posts
The ECU has a crank sensor that can detect the acceleration of the crank every time the cylinder fires. If you logged it, it crank acceleration would look like it pulsed.

When a cylinder misses, there is a lack of acceleration for that moment in time. If it happens for the same cylinder over and over, it logs this code.

I'm guessing that cams and compression ratios could change the pattern that the ECU is looking for.
 

·
[NEEvo President]
Joined
·
15,153 Posts
The ECU has a crank sensor that can detect the acceleration of the crank every time the cylinder fires. If you logged it, it crank acceleration would look like it pulsed.

When a cylinder misses, there is a lack of acceleration for that moment in time. If it happens for the same cylinder over and over, it logs this code.

I'm guessing that cams and compression ratios could change the pattern that the ECU is looking for.
Ahh, gotcha. Thanks for the clearing that up :)
 

·
aka mrubino83
Joined
·
4,161 Posts
The ECU has a crank sensor that can detect the acceleration of the crank every time the cylinder fires. If you logged it, it crank acceleration would look like it pulsed.

When a cylinder misses, there is a lack of acceleration for that moment in time. If it happens for the same cylinder over and over, it logs this code.

I'm guessing that cams and compression ratios could change the pattern that the ECU is looking for.
This is can also be caused by a light weight flywheel. The difference in weight is enough to throw off the crank angle sensor.

In certain cases this code can be an issue, but for some of us, is just an annoying phantom code. Any REAL cylinder misfire will most likely show up as p030X, cylinder specific.

A disable for this would be nice. FWIW the 8 and 9 evos disable this.
 

·
Registered
Joined
·
614 Posts
I use too always get this cel code...More on cold nights and while on e85... The car would still run perfect but I would get the code which was really annoying but I lived it because I read it was common issue... Now i dont get the code since my new tune which is great... I wouldnt disable the code tho since I would definitely want to know if i was having an issue specially knowing how e85 can be...
 
1 - 20 of 21 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top