wacboyjulian

So I picked up an Evo IX a couple months ago. I somehow enabled Limp Mode and trying to figure out if I should go to a tuner to investigate. This is a bit long so bear with me:

I was driving the Evo pretty hard 2 days ago, going WOT on several gears and pushing the engine for a mile or 2. I come to a stoplight and when it goes green, I get off the line gradually (not hard off the line) and then I try to pass two cars I see ahead of me. I'm believe I'm going no faster than 30 mph at this point before I start to try and pass.

I'm can't exactly recall exactly what happened but I think I was in 5th gear and tried to downshift to 4th. (Or maybe 6th to 3rd). I believe I missed the shift and the car was in neutral for a second or two.

I press the gas, realize my mistake and try to shift back into 5th. By this point, my foot is pressed to the floor trying to gain some speed and then I realize the rpms are flagging badly and I can't seem to get past 2K rpm.

By this point, my heart is in the pit of my stomach , pull over and rev it gently. Still no rpms past 2K and almost sounds like the Evo is sputtering. I text the previous owner of the Evo (he's always willing to give me feedback or advice and he took great care of the Evo) and he tells me its in Limp Mode. I shut off the engine, wait 5 minutes, and restart. I say a very heartfelt prayer and press the gas. It works. No limp mode. I drive cautiously home (about 2 miles drive) and don't feel/see/hear anything abnormal and let it idle for a few minutes before I shut it off.

I take it for a spin the next day hoping that it was a one-off but to my dismay, when I get past 4th gear, the Evo went into Limp Mode AGAIN. I curse loudly and shut off the engine. Repeat the same thing I do last night and Limp Mode is gone when I restart.

I drive cautiously for 10 minutes, checking my boost/oil temp/ rpms. No problems as far as I can tell. (I'm just unsure since I've only had the car for a couple months!) Then I start going up to 4K/5K in rpms in all gears, no problems. After some more test runs, I go WOT several times to see if boost is holding and notice no abnormalities. Run through the gears, Evo pulls strong. Boost/oil/AFR gauges seem normal. I even try a quick two step to see if it holds boost and 2 step works fine.

Drive around for another 30 minutes, basically trying to determine if there is any "trigger" or specific action I do that caused it. I find nothing. Then I let it idle for 5 minutes before I call it a night and park the car.

Evo is stock besides Blitz Nur Turboback, HKS Intake - (checked the MAF but it seems like its on firmly), ECU Reflash and Tepha v7.

Basically, I have no idea what triggered limp mode. I'm not mechanically inclined so I'm wondering if anyone had a similar experience or has any input. One of my questions is, if I'm trying to accelerate in a gear too high for the speed I'm going, is this potentially dangerous or harmful to my engine or turbo? I'm just trying to work different theories and thats the first one that comes to mind.

I realize Limp Mode can be caused by several factors but I'm hoping my story will bring some context. I'm going to drive it again tonight. If it occurs again, I'm going to see a local tuner on Thursday.

evo8426

iTrader: (27)

There is not a limp mode. Do a boost leak test and check to make sure all couplers are nice and tight on all areas of the intercooler pipes. The car is barely driveable if you have a leaking intercooler pipe and struggles to go past 2000 rpm if it is bad enough. Make sure all vacuum lines are in good condition without any cracks or disconnected from places such as the EGR valve.

wacboyjulian

.....really? So its purely a hardware issue most likely? Not hardware issue causing the software or ECU to go into some sort of "safe mode"?

ShadyLTD

You probably blew off a vacuum line or something when you got on it the first time. Check all your lines. Boost leak check is the best place to start

318bryan

I believe there is something like what he describes as "limp mode" to protect the car. My STi has done this exact same thing before and if i remember correctly it turned out to be either a wastegate issue causing it to overboost, or something with my manual boost controller. Only would happen in higher gears too

wacboyjulian

Thank you for the feedback guys. I talked to my tuner and he believes its something along those lines but I'll be seeing him Thursday to ease my stress.

iD33

Did a check engine light pop up? I would assume fuel cut initially but to many variables. Do you have a data-logger? One time i triggered the valet mode by putting my foot the accelerator and held it. The CEL light flashed indicating valet mode was on. Drove and the car cut out somewhere in the 3-4K RPM range, felt like fuel cut.

wacboyjulian

No CEL but I suspect the previous tuner removed all CEL warnings from the ECU. I know he removed some CELs for sure.

I can't even go beyond 2K so I don't think its valet mode (but I would be SO HAPPY if that was the case lol)

Part of the problem is my lead foot

iD33

I forget the process but are you willing to flash the ECU back to factory? Might be an avenue worth steering towards.

maikcat

one "tuner" has disconected the cel light from dashboard to prevent
it from lighting up...

Michael.

cmac04RS

iTrader: (1)

Hey the "tuner" who had at my car before I bought it did that. Hard to pass emissions via OBD with that one.

mt057

iTrader: (6)

Sounds kinda like NLTS. Vallet mode would be all the time. It could and would prevent you from going over a set rpm level though.

The NTLS would fall on its face if you went past the threshold to engage it without staying in it. I had played with my setings and put the trigger low. Long story short I had a hard time making it back from the grocery store after forgetting about it.

Lets say your threshold setting is 80 percent throttle. If you go over that the car expects you to shift at that or greater throttle. If you fall below the threshold while shifting it will enter a sort of limp mode and fall on its face. You will barely be able to get out of your own way.

You would have to have a taxtric cable and ecu flash to check it. The process is not hard if that is the issue. Hopefully, it is something simple.

The vallet mode, You would see the cel flash when you turn the key to the on position. It would be active until turned off by turning the key to the on position, then holding the gas pedal to the floor for about 10 to 15 seconds. The cel will flash fast or slow to let you know which mode it is in.

You can turn off all CELs with out disconnecting the light in any way. I guess someone could take the time to remove it but that would be more difficult then just turning them off.

GL

Biggiesacks

tuners will usually only disable codes for the rear o2 sensor and maybe emissions equipment. It sounds like valet mode but i dont know if that can be engaged with the engine running or not. Time to invest in an Openport cable and ecuflash. One of the best mods i ever got for my car.

zac-mac

Same thing happened to my car and i freaked out, turned out to be a punctured coupler. Check all your couplers and piping for leaks.

evotuner04

iTrader: (45)

What is this valet mode? Something thats turned on and would be on all the time until you turn it off? Hence if you were expecting others to drive your car...?