2006 wrx flashing cel under wot

[Inflict89]

hey all, i have done all the typical misfire checks. I've done the following:

Clean Maf sensor
New spark plugs (gapped at 0.028)
Inspected all coil packs (did swap 2 to 1, but since no stored CEL i have no idea what cylinder is misfiring)
Completed a compression test this morning
Cylinder 1: 122
Cylinder 2: 124
Cylinder 3: 124
Cylinder 4: 120

Replaced in-tank fuel filter and fuel pump sock as well.

Did a datalog (included below) and only see roughness counts on cylinder 3. Swapped coilpack with cylinder 1 with no change***8230; I was thinking possibly injectors but looking at the datalog i'm assuming it's not that.

Only modification change in the last 6 months is a new clutch and lightweight flywheel. Car was tuned with the factory clutch kit and flywheel, so i'm unsure if that would contribute like it used to for the ej20's.

Any help would be appreciated, thanks in advance.

PS Data log was cut short due to having a dinosaur V2 and sometimes it stops datalogging mid-way.
Datalog: https://docs.google.com/spreadsheets...it?usp=sharing

modlist:
vf48
13 sti tmic
walbro 255
invidia catless downpipe
spt intake
grimmspeed ebcs
protuned back in 2014 by Sean at Church in LA

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[BlackFighter]

Car was tuned with factory kit and flywheel

What do you mean by factory kit? There is no factory kit from Subaru to tune. Lightweight flywheel and light crank pully sometimes work funky on idle and WOT. If not, then go get it tunes on a dyno.

[Inflict89]

Originally Posted by BlackFighter

What do you mean by factory kit? There is no factory kit from Subaru to tune. Lightweight flywheel and light crank pully sometimes work funky on idle and WOT. If not, then go get it tunes on a dyno.

Factory clutch and flywheel. edited first post.

[benflynn]

I swear I remember lightweight flywheel giving misfires somehow

[BlackFighter]

clutch and lightweight flywheel

It says in your post "lightweight flywheel". What is a factory tune kit? If it was tuned with a stock flywheel and then you put in a lightweight FW. That might be your problem.

[Max Capacity]

Yes, I seem to recall that a LWFW that was was 14lbs. would cause an issue. I think my LWFW is 17 or 19lbs. in my 2005 Legacy GT. I also recall from back in the day, not to also do a LWCP.

[BlackFighter]

Yap, Mine was giving me major issues until I got it to Jr and he tuned it properly.

[Inflict89]

Originally Posted by BlackFighter

Yap, Mine was giving me major issues until I got it to Jr and he tuned it properly.

Quite possibly the issue. Just confirmed weight on the flywheel and it’s 12.5lbs. Would a retune solve the issue? I’m almost leaning to throwing a factory flywheel back in.

[BlackFighter]

If its a good tuner and if that is the problem then it should fix the issue. But it has to be a dyno tune, not some e-tune or "Factory Tune kit" which I still have no idea what that it.

[BlackFighter]

What FW is it?

[Inflict89]

Originally Posted by BlackFighter

If its a good tuner and if that is the problem then it should fix the issue. But it has to be a dyno tune, not some e-tune or "Factory Tune kit" which I still have no idea what that it.

I never said anything about a “factory tune kit” i said it was the factory kit and flywheel which I edited to read factory clutch kit and flywheel.

It’s an Action Clutch lightweight flywheel.

I’d like to move to a different tuner as Sean is a pain in the ass to get a hold of. I wish Ron did ej’s still and his dyno wasn’t broken... I guess Yimi sport would be a good option.. I’d like to avoid an e tune as this is my wife’s car and rather it all get dialed in during one session.

[Inflict89]

Update. Decided to unplug the maf and start the car... low and behold she idles perfect.. leads me to think this:

Bad maf
Bad front o2
Post maf leak

I’ll be putting together a smoke tester over the long weekend and see if I can rule that out before throwing parts at the thing. Anyone have any other ideas?

[K3rm1tth3fr0g]

Originally Posted by Inflict89

Update. Decided to unplug the maf and start the car... low and behold she idles perfect.. leads me to think this:

Bad maf
Bad front o2
Post maf leak

I’ll be putting together a smoke tester over the long weekend and see if I can rule that out before throwing parts at the thing. Anyone have any other ideas?

Replace the maf forsure if it's a 2006

[Inflict89]

Originally Posted by K3rm1tth3fr0g

Replace the maf forsure if it's a 2006

Yeah, I had taken the car to a shop a number of years ago due to some phantom knock issues. They said it was the maf and they “changed it”. I’m confident at this point they didn’t because the previous owner used RTV to ****ing put it in... needless to say I’ll be buying a new maf and will be trying to carefully remove the one that’s there smfh.

[connoredm]

Any update on this?

[Inflict89]

Originally Posted by connoredm

Any update on this?

Took the weekend off from any headache lol. Ordered a new maf sensor. Since the old one was installed improperly using rtv I’ll likely be doing this Friday night/Saturday as it’s my wife’s daily.

I’ll keep this updated till I solve it to help others. But I’m leaning toward MAF or front o2 at this stage.

[Inflict89]

Update. New OEM maf came in this evening so I got to work. Old maf was stuck on there due to the last owner using a ton of rtv on it... after some prying I got it off. Cleaned off the RTV and put her back together. Let idle relearn, took a quick drive around the block and everything felt way better than it had in a very long time... did a quick pull and no more flashing cel and pulled hard to redline.

This is a major reason why I stopped going to "reputable shops" as the last shop I took it to claimed to have changed it and charged me over $150... clearly it wasn't changed. At the end of the day I learned the engine still has great compression for having 105k on the clock.

Didn't take a pic of the mess that was on the intake***8230; but looking at the maf i'm sure you can imagine***8230; intake cleaned up nicely.