[EVO]Cookie

iTrader: (3)

Your getting into higher harmonics, your getting closer to your peak torque. If you have access to a dyno. I would put it on the dyno and clear the code run the car try to cause the code if you can cause the code have someone run the car for you. Walk around the car while it's running and listen for vibrations. If you can't hear anything making noise you can use a sound probe. If you don't have a sound probe you can use a long stick or rod you place it to your ear and you can hear things inside the engine and tranny while it's running. Just try to use something non conductive and be careful around moving parts.

Ricky Bobby

Asuming that I can locate the source of the vibration, what are my options? I mean, If the cams or twin disc clutch are causing too much vibration for the stock sensor, what do I do? Is there a way to bypass some of these systems through aftermarket management?

SOOB

^^^^^ Absolutely correct. I have the same exact problem(as well as numerous other '03 owners) and finally got the only, and most logical, explanation from both dealer and "Road Race" veteran mechanics. The knock sensors' sensitivity pickup is set too high(manufacturer F'up) and unfortunately has not been recalled. Vibration from the "straight cut" transfer case is being misunderstood for a p0300 "multiple misfire" by the knock sensor, when in fact, there is no misfire. But hold your pants, there is a solution. All you need is a reflash to set the sensitivity down on your knock sensor. A very common and easily fixible headache among most(if not all) '03 Evo owners. Hope this helps

Ricky Bobby

Is this a dealer flash or something done through a UTEC or tuner cable? this sounds right to me.... thanks for the heads up. This is the first I've heard of an actual fix that fits the problem.

[EVO]Cookie

iTrader: (3)

That sounds like an easy thing to try lower the sensor values. Stand alone is an expensive option. And if there is a underlying mechanical issue a EMS would be a big waste of money. If you have a lot of miles on the car you might want to get your compression cheaked just to make sure the lower end is in good shape. Bad rod bearings could cause a P0300.

Ricky Bobby

At first I thought mechanical issue as well. Everything seems to be fine though. Compression is good, The car runs strong under other conditions (other gears) and it consistantly occurs at the same moment in 5th. Under WOT it's not an issue and the plugs aren't fouled or anything. When looking at the datalogs it looks electrical. Either ignition issue (which doesn't seem likely) or sensor failure.

wrcwannabe

iTrader: (1)

He's been re flashed with the Mitsu fix, and it did not work, just like it hasnt for literally hundreds of other 03-04 EVO8 owners.

Culled from 8 months of viewing, culprits and sometime fixes:

ECU reflash
plugs, wrong heat range
plugs worn
carbon tracking on plug ceramic
plug gap
plug wires
bad camshaft sensor
camshaft sensor not in spec ( giving correct shape of signal )
noisy lifters
lifter pump up
Transaxle noise, 5 th gear shift fork slightly bent or damaged
downpipe hitting lower brace
downpipe leaks
exhaust manifold leaks
real knock
boost too high causing real knock
poor gas quality ( more frequent than you think )
bad connect on coil on plug
worn motor mounts
transaxle noise due to insufficent fluids
EGR valve problems
very poor tuned flash


Take your pick

Milburn

Ricky Bobby

referring back to this.... is there a specific setting that has been working best? I found out that I can manipulate it, I just need to know if it's case by case or if there's an actual setting that most turn it down too?

03evo8gsr

iTrader: (5)

i had this problem. my light comes on about ounce a month. i went through diff plugs, then went to some ngk 1 step colder. and they been working for me. my mods are bc272, headstuds, hpf licp, knn drop in,10.5hs, 3 dp, 3 cat back, rnr intercooler.

SOOB

Case by case. I had Road Race in So. Cal flash mine. They said some Evos need lower sensitivity settings than others. Depends on how much vibration your specific Evo generates.

Ricky Bobby

thanks for the heads up! I've got a tuner that can take a look at it. Wish I lived near road race....

lightspeed1

iTrader: (7)

Can this sensitivity be adjusted with ecuflash? I have had the dealer flash twice, input shaft replaced (tranny), and new rings (piston), by the dealer under warranty...with no salvation... with 66K on the motor, I will try anything!

Ricky Bobby

I asked my buddy, and he said it can be adjusted with it, but he's never done it. I have a UTEC on the way which I plan on running over my ECUflash.

lightspeed1

iTrader: (7)

Can you find out from your buddy whereabouts in ECUflash that adjustment is located?

Suckface

iTrader: (1)

as an update,

orginally had the ECU reflash and plugs changed.....

that didn't work, so I took the car back, changed out the wires and checked the timing, found it was off and replaced the belt and tensioner, and timed the car correctly.....

problem solved for a short period of time, with in 24 hours SES light was back on and the car was stuttering very badly, worse than before......

back to the dealership for another evaulation.....this time the replaced the input shaft in the trans and fifth gear......

picked up the car last night, no problems yet, knock on wood....took the highway to work today on purpose and nothing so far.....

lets hope that this works.....

apparently Mitsu has a recall for these parts as a possible fix for 03 with this problem, I will look into the work order #'s etc. and post them tomorrow....