Intermittent rough idle... kind of like a "hiccup"
Mar 12, 2007, 07:29 PM
#16
Your car is probably fine as is mine, and the dealership is probably right in this case. I actually had 3000 miles of constant P0300 misfire codes which were attributed to a faulty injector (all 4 were replaced, P0300 gone). This was when I changed plugs, wires, compression tested, boost leak tested, de-carboned, fuel injector cleaned, swapped coils, looked for exhaust leaks, and tested o2 sensors, and anything else I could think of. Car still idles rough, always has - I'm guessing its normal and the car was always making good power and never had a noticeable high rpm misfire like when your plugs are gapped too wide (popping). The CEL would just come on (especially in the rain with the wipers and defroster fan on). On a OBDII logger you could see the fuel trims getting out of whack and then the light would come on, the idle would get rougher until you reset the ECU and then it would run normal until the trims got out of whack again.
Last edited by Mr. Evo IX; Mar 12, 2007 at 07:31 PM.
Mar 12, 2007, 07:49 PM
#17
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Your car is probably fine as is mine, and the dealership is probably right in this case. I actually had 3000 miles of constant P0300 misfire codes which were attributed to a faulty injector (all 4 were replaced, P0300 gone). This was when I changed plugs, wires, compression tested, boost leak tested, de-carboned, fuel injector cleaned, swapped coils, looked for exhaust leaks, and tested o2 sensors, and anything else I could think of. Car still idles rough, always has - I'm guessing its normal and the car was always making good power and never had a noticeable high rpm misfire like when your plugs are gapped too wide (popping). The CEL would just come on (especially in the rain with the wipers and defroster fan on). On a OBDII logger you could see the fuel trims getting out of whack and then the light would come on, the idle would get rougher until you reset the ECU and then it would run normal until the trims got out of whack again.
BTW, do you have a code reader, or did you have to go to a shop with an OBDII scanner?
Mar 12, 2007, 07:54 PM
#18
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Your car is okay, '06 EVO's have a lumpy idle, that sounds sounds as if it had a cam, like someone pointed out here earlier. Mine has been like that since day 1, it now has almost 7200 miles and it ran 13.1 bone stock, stop worrying man, just drive it and enjoy it!!!
Cheers!
Cheers!
Mar 12, 2007, 08:28 PM
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Your car is okay, '06 EVO's have a lumpy idle, that sounds sounds as if it had a cam, like someone pointed out here earlier. Mine has been like that since day 1, it now has almost 7200 miles and it ran 13.1 bone stock, stop worrying man, just drive it and enjoy it!!!
Cheers!
Cheers!
Aug 23, 2010, 04:29 PM
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Have the same problem in my 08 evo x, but it only happens sometimes. It drives fine and pulls strong, it's just at idle , and it pisses my off sometime, but i can't figure it out. The car has a catback , maybe that's the problem.
Nov 2, 2010, 06:43 PM
#21
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Hey I know these threads are pretty old but yeah the lumpy idle on the evo 9 is pretty much how its described here, my evo 9 has 88,600 miles and yeah it idles exactly how you guys have described. It still pulls very hard and idles at 900 rpm, everything normal. I even checked vaccum readings and its normal at around 19 hg thank god 
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