I don't know what the heck is goin on but my 05 MR is reaching rpm cut off at sporatic rpms. The 1st time it happened it was at 5800, the second time it happened it was around 6300.. where the check engine light came on. I reset the ecu, the CEL went away but just did it again today at 5800 again.

I'm stumped.. I've never touched the ecu and it just started happening out of no where.. any ideas guys? Thanks in advance..!

Mods: dp, test-pipe, w/ catback

 

If you are not tuned then you are probably hitting fuel cut. With the cooler air you could be hitting higher load cells than you were in warmer temperatures. You need to get the car tuned.

 

fuel cut, get tuned, or buy a tactrix cable with either you tuning it or a eflash from a tuner like jestr...

 

Thanks for the replies guys! Now that I think of it, it did start happening when the weather got colder out. Do you think the weather has that much of an impact..?!

 

yep...im getting too...im yet to get it tuned...but i just got the cable and have been messing with my limiters...and it seemed to go away when i raised the boost limits!!!

 

yes it does make that big of a impact. get a flash. i would also get a boost controller. the cooler temps and tbe are causing you to boost higher and hit fuel cut

 

tune tune tune....

 

thanks for all the replies! Now the big question is that since weather is such a big factor, if I took the car to get tuned in the winter will it run differently when summer hits or will the ecu "learn" with the different weather/temp conditions..? Thanks for any input!!

 

If you tune it in the winter the worst that will happen is you'll be rich in the summer. A good tuner should be able to compensate for that though. Colder air is more dense, obviously. With more dense air you are going to want more fuel to make use of the combusion, therefore making more power. This puts you in higher load cells in the ECU. Any tuner worth his salt will be able to tune your high load cells for an AF ratio that is comfortable for you and may tune your slightly lower load cells a bit more lean so you're not pig rich during the summer.

 

I have a 2005 Evo with dp,catback,testpipe,o2 housing,headers,intake,upper ic pipe,clutch, flywheel, and blow off valve and i dont have it tuned and it doesnt get fuel cut off. So maybe its not ecu issues.

 

It is definitely fuel cut, neweraevo8. Why you aren't hitting it despite foolishly running your car untuned with all those mods is a mystery, but for this guy, it's definitely fuel cut. An exhaust without boost control and a tune really is senseless - I'm not sure why people still do this after countless threads just like this.