My Evo is running like crap.Can't figure out whats wrong.
 

UPDATE : I know this ALOT to read so I'll sum it up,you can still find the details in the text below.
About two weeks ago car started idling very ruff.Car is shaking alot,revs dropping,stalling,giving gas on it's own,and is running VERY lean.
While driving,the car is surging and bogging,no power between 2-3k revs at light throttle then around 3k "breaking free",better when pushing pedal harder.
Car threw 2 codes :
P0125 Insufficient Coolant Temperature for Closed Loop Fuel Control
P0505 Idle Control System malfunction
Tried alot of things(put them in bold),none which seem to fix my problems.


OK I am going to give you as much info as I can so that hopefully someone will be able to tell me whats wrong with my car.
First my car: a 2007 IX 6-speed with 21k miles and these mods:
Ported exhaust manifold
Ported tubo inlet housing
Ported stock turbo
Test pipe with CEL fix
Perrin air filter with stock MAF pipe(installed about 3 weeks before trouble began)

A few months ago car threw a P0170 which turned out to be the front O2 sensor.Replaced it with a generic one since :mitsu: wanted 420$ for a new one.
CEL went away and car drove fine up until about 2 weeks ago,that's when the real trouble started.

I drive the car out of the garage,it's idling at around 1000rpm but the whole car is shaking like it's about to stall.I was just about to leave on a holiday so I had no choice but to drive off.
Shaking went away and car drove like normal.After about 60 miles of driving mostly on the highway things get bad.

The car starts surging and it feels like it's constantly braking on the engine and then accelerating again when I just hold the pedal to keep speed the same.
My speed and revs don't seem to change while it's doing this and it happens at a certain rythem.
The higher I go in revs the faster the rythem and the harder the "braking".
Car has no more power between 3-4k revs.
Once past the 3-4k mark however the car pulls hard but it doesn't feel as hard as normal and once off the highway idle starts going crazy: nearly stalling,starts revving on its own.
Also have to give alot of gass when driving off or I stall.

My guess was it's the Perrin filter since it was only on for a few weeks,no tune and first time I drove it in really hot weather.
So took it off,checked and cleaned MAF which looked fine,unplugged it which made it even worse so pretty sure it's not the MAF.
When I have reinstalled my filter and the car has cooled down I try again.
Idle still crazy and wants to stall most of the time,throttle feels like its sticking,
I now have no power between 2-3k revs (giving gas lightly just so you can feel the car accelerate) and it feels like someone is pushing my car backwards.
When I then push the gaspedal harder (halfway or so) it shoots forward like it breaks free.
When I immediatly press the pedal past halfway the car doesn't lag between 2-3k or alot less anyway.

So 3 days later I finally get a CEL.Read the codes and got these 2:
P0125 Insufficient Coolant Temperature for Closed Loop Fuel Control
P0505 Idle Control System malfunction
I noticed my coolant overflow tank was completly empty so filled it up to the desired level and hoped that this would solve the P0125.
P0505 didn't know what to do yet so erased them both.
Next day new CEL.I was convinced it was going to be the P0505 since it was still idling like crap but it was the P0125,removed it,next day again P0125.
Funny thing is the P0125 shouldn't cause any drivabillity issues,especially not the ones that I am experiencing.
So here's what I have done so far.

*Removed and cleaned the throttle body

*Took out IAC valve,turned ignition to ON but nothing happens.I hear 2 clicks that appear to be comming from elsewhere than the valve(more passenger side) and it doesn't move.So it appears I found the problem.
Just to be sure before I spend 500$ or so on a new one I take my multimeter and measure the pins.
Measured pins 1&2,2&3,4&5,5&6 and they all read around 30.5 Ohms(should be between 28 and 33).So now the IAC valve is fine?I measured the wire harness and,12v pin 2 and 13V pin 5 so cable is fine aswell.
Plug it back in,turn the ignition and again nothing???
Put it back in the TB,reinstalled everything,ignition ON and hear several clicks now.
Maybe bad contact or so and it works sometimes,sometimes not?

*Checked TPS(visually),how do I measure this?

*Took out spark plugs and they were really white so car is running lean.Cleaned them using a wire brush and brake cleaner.
Checked gap and it was OK.Spark plugs are NGK ILFR7H gapped at about 0.55mm(NGK site says between 0.5-0.6mm).
Put them back and it was even worse.
Whole car was shaking and rattling badly and the exhaust sounded like it was about to rattle of.Got better after a while.

*Suspected car was running lean due to Perrin filter so put airbox back.Didn't solve the problem.

*Rechecked spark plugs after few days to see if it was still running so lean without the Perrin,it was even worse.Spark plugs were VERY white.
Maybe my car is running this bad because it isn't getting enough fuel?But wat is causing my car to run this lean?

*Disconnected IAC valve,not much difference,only idled.

*Disconnected TPS,not much difference(idle)

*Disconnected both,got worse,got P0120 TPS/Throttle pedal position sensor "A" circuit malfunction

*Adjusted BISS,can turn it all the way to the left and right with hardly any noticable difference.

*Tried the idle "learning" procedure.Let car run warm,adjust BISS,disconnect battery,reconnect after 30min,let idle for 10min.Doesn't work,not even when pulling out ECU fuse.

*Put more slack on throttle cable

*Removed mechanical CEL fix from test pipe.Been driving around for 3 days and still no CEL.How long should it take for the rear O2 to figure out there is something wrong with the cat?Maybe rear O2 is broken?
Same with front O2.Shouldn't it give a CEL if my car is running way to lean?

Think that's about it.Got another CEL today but this time it wasn't the P0125 that came back,but the P0505 even though nothing has really changed?
I'm totally clueless now.One last thing I want to mention is that sometimes it wants to stall all the times and it shakes and rattles but other times it's just the opposite.
It then starts revving on its own,when I let my foot of the gas it keeps on going for about 2 seconds before slowing down
and when standing still and tapping the gaspedal you can hear it "hang",like it's sticking and then revs drop.
Thing is that then I don't have the huge 2-3k lag,car doesn't shake and is actually pretty driveable but then I turn the ignition off and on and it's the same crap again:crap:
This car is my dd and this really sucks.Because it is running so lean I am afraid to drive it(I still do but I have no choice)
and because of all the shaking and the bogging it is really embarassing to drive around cause I look like someone who has a steering wheel in his hand for the first time.

Sorry for the long post,I just want to get this resolved as quick as possible cause it's driving me crazy.

woah...to much to read!!!...

do you have stock snorkel?...if so make sure clips are still in...

From reading the car is untuned correct?? If its not tuned no worries

It could be an issue with that front O2 thats in there. It sounds like the ECU doesn't have a clue how to fuel the car.


Only time I have ever seen a P0125 was due to a tuning issue

Yeah sorry just wanted to give as much info as I could.
Have stock snorkel and clips are in.

Woah what did you gap your plugs at?! 0.55mm I would double check that against whatthe guys on this site do. I could DEF. be wrong, but I don't think that's right.

Yes my car is untuned.Removed Perrin because it was running lean but spark plugs are still VERY white.Figured if I put stock airbox back my AFR's will go back to normal,guess not.
When I got the P0170 with my OEM O2 sensor the car was running rich and had loss of power.Replaced it and fuel economy went up by half and car felt more powerfull.
Now it looks the other way around and way to lean.Going to measure both front and rear O2 tomorrow.

0.55mm is around 0.021-0.022"
Most people on here seem to run between 0.024-0.028",NGK.com even says 0.032" but on NGK.de it says between 0.5-0.6mm so I don't know if I should regap them or not?Running 98 octane here.

O ok no you seem like your running with the right gap then. Just a different way of saying the same thing.

boost leak test?

Made a crappy one a while back with some stuff I had lying around but it was leaking so I couldn't put more than 9 psi on it.
Probably way to little to spot any leaks.Going to get me some stuff to make a decent one.
What's the stock boost on a IX?

i belive 19psi..but yea 9 psi is way to low especially if leakin from the tester...

that'll be a great place to start

My car ran poorly when i swapped to a new intake pipe and filter. It was a perrin also, thought it would be ok because of what I was told but that was not the case. Th car ran very poorly i did much of what you did. It stalled, needed a lot of gas was very finnicky etc. I switched back and it took the car a little while to adapt. But if you don't have a tune I wouldn't be worried. Your car won't like an intake unless it's tuned specifically for it.

check both coolant temp sensors on the throttle body. I am willing to bet this is whats wrong. Do you have a buddy that you could try his quick? or access to someone with evoscan who can see live data of what the coolant sensors are reading.

Double check your front o2 sensor connections. I had one where it was literally just enough to get the sensor to activate but it would randomly go rich or lean because engine vibration would cut and reengage the connection randomly.

So eventually it fixed itself?

Will check these tomorrow.Unlike in the US Evo's are very rare here and I personally don't know anyone who also drives one.Maybe I can find a Belgian Evo forum and hopefully someone lives nearby and is willing to help.
If I could just switch out parts it would make it alot easier to find the problem.
I have Evoscan but don't have a proper cable.

Will do that.The one that is in now is just a generic one,got it really cheap so maybe it's already broken again.I will check the wiring first and will then test with multimeter.