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throughout reading this, bear in mind, i have not done anything to the car for quite some time, i haven't even popped the hood.
yesterday i started my car after work with my starter, only to notice, as i was walking to the car, the idle was inconsistent....... HUNTING IDLE!
got in the car, drove home only to notice that at light to moderate throttle, the car was a little hesitant..... MISSING!
got home, did some checking and found nothing. no cels. pulled my front o2 sensor from the harness, same with trhe maf, nothing. all gave cels and made the hunting idle worse.
noticed a little shaking at one point.
this am, drove into work, flogged it a few times just to see if there was anything happening in the higher rpm and nothing.
then it happened, i was idling in the th's drive thru and whamo, crazy amounts of hunting mixed with violent shaking.
GOTCHA i proclaimed!
cel was on and off flashing and then going away. grabbed my cobb to see if anything was in the ecu and i got;
cylinder 1 misfire
cylinder 3 misfire
spark plugs are champion double platinum changes every 10k miles.
would bad plugs cause issues or is it a sign of a failing/failed motor?
thanks guys.............

mods are
Fuel & Tuning:
Cobb AccessPort
ProTuned

Exhaust / Intake:
invidia bellmouth downpipe
invidia g200 cat back exhaust
injen cold air intake
walboro fuel pump
tial 44mm ewg
ultimate racing up pipe
power enterprises 800cc top feed injectors
fp green
perrin equal length headers
css fmic
 

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All I can say is get a compression and leakdown test first and go from there...

Before that though, check your oil level. What does that look like? Unscrew the oil filler cap on a warm engine and check for smoke coming out of there when the car is running. Rev it a little and check too.
 

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take off ur oil filler cap while the car is running, and see if there is smoke coming out of there...if so u have some motor issues...if not u can relax and hope its bad gas...can u log the car and send it to your tuner?
 

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Good suggestions so far from everybody.

Food for thought, Subaru in COLD weather recommends that you have more than a half tank of gas, so that condensation doesn't build up inside the tank.
 

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can you check your short term and long term fuel trims to see if you're ingesting air that your MAF isn't metering right? look for spots where your o2 sensor has determined you need a lot more fuel (indicated by large trim numbers). sounds like you haven't ruled out an air leak just yet.
 

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Discussion Starter #12 (Edited)
thanks guys..............
old plugs came out, not fouled, just 'rich' looking. put the ngk iridiums in, drove the car and the same issue was just as present.
NOT THE PLUGS!
went back to the shop, hooked it up to the obd reader, nothing came up.
swapped the map sensor with another, not that, cleaned the maf, no different.
inspected the injectors for signs of them popping up or unseating, nothing.
unplugged the o2 sensor and the car ran better, but still doesn't feel 100% normal.
drove home with no o2. keep in mind, that i just swapped out my old o2 sensor for a brand new one about 10k miles ago.
connected the o2 back up this am, drove to work to the same issues as listed before. stumbling, hunting idle, no cel.
in thinking about everything, i am stupid.
i thought back to when the car was somewhat stock earlier last year when i first got it.
the shaking, lower than normal idle happened once or twice when the following occured;
drove the car for a bit (home from work), get home, turn the car off, go inside, open the garage door, get it, start the car, the idle got all weird (lower than normal ~4-500rpms) and i had to float the gas pedal to make sure it wouldn't stall.
to put everyone's mind at ease........... OKAY MY MIND!
before i did the fp green, injectors, up pipe/ewg and headers, we did a compression test on the car and it hit 135psi on a stone cold motor.
the car was tuned 4 times last season for varying mods and always pulled like a champ.
the motor is fine. further to that, between oil changes, 5qts. in, 5 qts. out.
no smoke, coolant is also fine.
i was worried yesterday, but in a way, i am now starting to find this fun in a strange way.
 

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Discussion Starter #15
front o2 sesnor!
took the car into a local dealer BUDDS SUBARU and had them look at it.
the guys checked everything and noticed the hunting was going from cylinder to cylinder. that ruled out anything cylinder specific, IE, coil packs, plugs, injectors.
unplugged the 02 and whamo, ran perfectly.
 

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Discussion Starter #20
update!
started the car thursday afternoon and it got all crazy on me again. hunting idle, hesitation under light to moderate acceleration. went to my tuner on friday afternoon and we re-sealed the maf housing, reset the ecu and did some other hunting.
drove home with the same result.
hunting idle & hesitation.
saturday afternoon, going out, car was @ operating temp. idle got really crazy, violent shaking. threw a cel. cylinder 3 misfire.
unplugged the o2 and now the car drives fine. pulling the car out of gear into neutral i do get a little bit of a hunt, but that lasts for 2 seconds then settles out @ 900rpms (tuned to run).
we checked the o2 @ my tuner and it is reading. so the o2 is not pooched.
after thinking it was the o2 sensor originally and seeing this happen again (same cycle), i know now it is not the o2.
ideas?
 
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