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02' Stage 2 WRX W/ Accessport: Potential Overboosting and AF Learning 1 Spec

9K views 26 replies 5 participants last post by  Jackstand Johnny 
#1 ·
Hi everyone. So I finally got my Accessport back from Cobb after the screen got cracked. I also flashed my ECU back to the Cobb OTS stage 2 93 octane tune after making the rookie mistake of running a custom stage 2 tune that the previous owner of the AP bought. Anyways today I decided to do some datalogging. The biggest issue is that my car has the 4EAT automatic transmission(dont hate, fake leg, cant clutch). I couldnt get up to redline 3rd gear. I was able to get to about 5500 RPM before I had to let off. I checked my gauges on the AP and it said I peaked at 19.75 PSI!!! Thats BAD, right? Im definitely overboosting for my setup? Factory TD04, injectors etc. Im only setup for a stage 2 93 octane map. I didnt even hit redline and I was at 19.75 PSI and climbing. Any ideas on where I should start looking for problems? It was a smooth roll on the throttle and it never once bucked, stuttered, surged or anything. Just a smooth and quick climb to 5500 RPM.

Also my A/F Learning 1 shows +5.45% fuel added at certain times. When Im driving using the cruise control or consistent speed the AF Learning gauge is at 0.00 most of the time. Other times its reading as much as -3.xx% but 5% is the most Ive seen on the plus side of that. Its never been over 8% either way, so should I not worry about it? Im sorry but Im currently unable to actually upload my data logs or connect my AP3 to my laptop at all because its got problems and doesnt recognize ANY USB device. I also wasnt able to finish installing the Cobb AP Race software because of this. Thanks in advance for you help.

PS heres just a list of what been done to my WRC so yall know where its at:

Cobb stage 2 93 octane OTS map
K&N drop in panel air filter
Perrin 3" catted downpipe(NOT divorced)
Factory STi catless up pipe
Stock WRX 2.5" catback exhaust
Grimmspeed Air/Oil separator
NGK Platinum plugs gapped to .028"-.030"(all evenly gapped I just cant remember exactly what I gauged them at)
Stock TD04 and everything else
4EAT automatic transmission

Also I had a leak at my airbox because the K&N panel filter has a fat flange and is a bitch to seat properly BUT as far as I know its seated correctly and the airbox lid is fully latched on the backside and all is well. No loose connections or leaks at the MAF piping/airbox as far as I can tell.

Thanks so much for your help!
 
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#3 ·
the 4EAT is way better than the 5MT anyways :D VTD/VCD FTW!

start by replacing all your vacuum hoses on your BCS. they are 14 years old and whether they may not looked cracked or not, its almost guaranteed that they are leaking somewhere. considering its like $5 of hose, its worth it either way. and also make sure your BCS is working... it as well is 14 years old and should be replaced regardless. even if its clicking when tested, the internal diaphram can be leaking. you can splurge for a 3-port but it will need tuning (cobb has a map) or just get a new oem one for cheap. if sticking with oem dont forget a new restrictor pill! but the 3 ports do not use one so factor that in to your decision.

i had a buddy overboosting and it was just a simple replacement of his bcs that solved it.

good luck :D
 
#4 ·
Thanks guys. So Ive already replaced my vacuum lines relating to my BCS, turbo and wastegate. I replaced them all with silicone a few months back and reinstalled the original restrictor pill. I triple checked that it was in the correct line. Im currently still using the factory 2 port BCS. a while back I tried using a Grimmspeed 3 port EBCS with one of the custom XPT stage 2 maps that the previous owner of the AP3 had purchased but quickly realized that was a bad idea. I started having engine problems which ended up being a complete coincidence when I found out that 1 of my coils had actually backed off and came loose. Still before I found out the real problem I got spooked and put everything back to the other XPT stage 2 tune(I recently realized that too was foolish and am now running the Cobb OTS stage 2 map that I mentioned in my first post).

Boo-key: I thought that was the case about the boost tapering down before it hit redline but I wasnt 100% sure. Thanks for the confirmation. I have not tried the low wastegate map. I didnt realize there was one. Cobb makes a free OTS map for this? Does anyone know how big a difference it makes in the powerband compared to the regular stage 2 93 octane map?

Titter: Ill look into that wastegate being a potential problem. As for replacing the factory BCS with another factory unit, Im VERY broke right now. To be honest Im down right dirt poor. Been out of work for a while after losing my leg and a few months back I lost my disability benefits so its been really hard trying to find work and makes ends meet. If I were to replace my factory BCS it would probably be for the Cobb 3 port EBCS. I know its $115 which is probably much more expensive than the factory BCS but if I replace it it'll have to be the kind of thing where I only replace it once. That is unless I can find another factory BCS for like $10 shipped or something lol.

Thanks so much for the help guys. I really appreciate the positive feedback. It seems to be a rarity on most other forums Im registered with. How could I test the BCS and wastegate for being faulty?
 
#5 ·
Well Im definitely overboosting. Im thinking about lengthening the wastegate actuator arm a couple turns to try and bring the boost down. 19.76 psi at 5k is way too high. Would this help? Does anyone know what size C-clip I need? I cant find that info anywhere and I want to have a stack of them handy BEFORE I remove the one on my arm. Im 99% sure my restrictor pill is in the correct vacuum line but if it wasnt, would this cause overboosting? Its not spiking from what I can tell. I checked my logs and the boost is consistent all the way up the rev range. Any thoughts?
 
#6 ·
Are you catless? 2.0 or 2.5? Do you have an ebcs? Sorry if you've already answered these questions and I didn't see. If you don't have an ebcs, you might want to add that to your set up. It may help the overboosting. It's only around $100 and Cobb ots map compatible.
 
#7 ·
Catted DP, STi up pipe, factory catback. 2.0l factory 2002 WRX engine. The EJ205. Factory 2 port BCS. The problem is not only am I broke, but Im in debt a few thousand dollars right now. Ive been out of work on disability from losing my left leg but as soon as I got my prosthetic my disability benefits were cancelled, even though I couldnt walk with my new leg yet. They didnt see it that way. I now hafe 2 legs so theres nothing wrong with me is how they look at it. Im still unable to work but have no income, so Ive been getting into debt just to pay basic bills and eat. I cant afford to buy anything for my car right now other than gas and insurance. Thats why I was hoping adjusting the actuator arm would help, since its basically free other than the expense of a few spare C-clips.
 
#11 ·
Well I could only upload them as zip files. Ill try something else but you can download these, extract them to a file then view them in a spreadsheet program. Im using OpenOffice. If you use Open Office you just need to make sure that you only select "commas" when it asks how you want to format the apreadsheet. Otherwise the columns are pushed all out of alignment and its very hard to decipher what value goes to what section. Ill try to find a way to make this easier.
 

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#12 ·
I saw what Cobb was talking about though. On more than one occasion(several datalogs) you can see how the boost appears to spike from 14 or so up to 19 or 20 and then back down to 14 or so in a single cell on the spreadsheet. I dont know what could be giving those false readings if thats indeed what they are. Theyd have to be, right?
 
#13 ·
Ok lets get this all straightened out. First off please take a proper pull. That means 3rd gear ( for 5MT ) or 4th gear ( for 6MT ) We need you to take a 100% throttle run from 2500RPM to 6000 RPM. without that It will be difficult to get all the numbers to line up so we can tell why your over boosting. Also try google drive. Its a free service and you can post spreadsheets there and share them so we dont have to download unknown zip files onto our computers.

hope that helps
 
#14 ·
Due as Ive dtated several times now, I have the 4EAT AUTOMATIC TRANSMISSION. So the best I can do is 3rd gear. Also theyre not unknown zip files, theyre my datalogs as weve already established. Why would I register here, make an introduction thread, post up in several threads, and spend all this time here just to share a virus or malware? Whats the payoff?
 
#15 ·
I already have Dropbox and that does spreadsheets. That works basically the exact same as Google Drive, yeah? Cloud storage, sharing between PC's and mobile devices etc? Ill try that instead. Downloading software because one person on an internet forum says to makes as much sense a downloading zip files to your computer based on the word of the person aking you to look at them.
 
#17 ·
Ok heres the files from Dropbox. Hopefully yall can view them:

https://www.dropbox.com/s/pquxvhpzpn8oly0/datalog30.csv?dl=0

https://www.dropbox.com/s/moxf9jazbuv4p43/datalog31.csv?dl=0

https://www.dropbox.com/s/6e04qtfte0tp4aq/datalog32.csv?dl=0

https://www.dropbox.com/s/ot6c5pyl1snkh7y/datalog33.csv?dl=0

https://www.dropbox.com/s/qbae8gnv3mra4dj/datalog34.csv?dl=0

Thats all of them. The last 2 I THINK are low load low speed logs when I logged some fine knock learning problems Im also having. The first 3 I believe are the only ones pertaining to my overboosting but they all might show that Im overboosting throughout the powerband.
 
#18 ·
Check out cell #469 on datalog 32. Thats where it just jumps from 14 PSI to 19 and back down to 14 PSI in a single cell. I believe datalog 33 shows the same thing. This tells me its gotta be something faulty with how its being recorded and not my actual boost, BUT even if you exclude that anomaly it would appear that Im still overboosting throughout the powerband, right? As Im hitting over my target boost?
 
#24 ·
Thanks KamikazeI read that article on the one on why turbos fail but nothing popped out at me as to why mine would be having problems. I got my car from a very conservative female driver who got it from an older woman who had it registered as a diplomatic vehicle. It only had 91k original miles, was meticulously cared for and was completely stock until I got a hold of it. I have been religious about its maintenance and have always kept a close eye on things. The moment I started seeing these problems I posted them here. I cant imagine my turbo failing on me and Ive checked the vacuum and boost and intake lines and hoses at least 2 dozen times by now and never found any kind of a leak other than once when my airbox might have had a possible leak from not being able to get the K&N filter to seat right but I made sure the box has a proper seal.

The only thing bugging me is whether or not I put the restrictor pill in the correct line when I replaced my old vacuum lines with silicone ones. I'm 90% sure I did, but could having the pill in the wrong line cause problems like this? Is there a way to bench test my stock BCS to see if THATS going bad? The worst part of it all is I dont even know if Ihave a boost problem at all after seeing that 19 PSI spike show up in my datalogs as more of a computer error than anything. Im way more worried about my feedback knock and fine knock learning now. Did anyone see those by chance? Theyd be the last 2 or 3 datalogs I posted. They were always at 0.00 until a few days ago. Now tonight the feedback knock is jumping around a lot more than the fine knock learning. I can NOT afford any engine problems right now. Im already considering filing chapter 11 bankruptcy. If my car breaks down and its serious, Ill have to sell it. PLEASE HELP! Thank you all for the help so far. I'd be a nervous wreck if I didnt have yal here to talk me through it.
 
#23 ·
Yes exsactly. My target boost is 17 PSI. So I guess if you look at it that way, and it looks like other than that 19.7x PSI blip that seems to be an error on one of the computers faults, then Im hitting around 14 or 15 PSI around 4k. If thats the case then I guess Im actually UNDERboosting...right? Or would I be hitting my target boost if not for this curious anomaly of spiking to 19.7x PSI for a fraction of a second? Ive been considering switching back to the regular 93 octane stage 2 map from the low wastegate map Im using now for that reason and also because I didnt start getting these weird knocks showing up on my gauges until after I ran this LWG map, but Im worried that Ill seriously blow something up if I am in fact overboosting or getting boost spikes. Goddamnit I really need money so I can get a Cobb 3 port EBCS.
 
#25 ·
Ok well this thread basically puts my overboost problem to bed. ently this is pretty common. Cobb even answered back and a guy posted the reply from Cobb. Its exactly what I have going on.

https://www.reddit.com/r/subaru/comments/27n2ft/39lbs_of_boost/

NOOOOW...I wonder since Im having issues with my fine knock learnign and my other knock gayge if its safe to switch from this low wastegate map back to my previous stage 2 93 octane map. I DID only start seeig this screwed up knock numbers after flashing this LWG map but I dont see how they could be related. What do yall think?
 
#26 ·
I'm I'm back again. This time my AF Learning 1 is going past -8. We just had a bad snowstorm and I drove in it quite a bit. It seems like right after the snow passed my AF learning 1 has slowly been dropping from -7 to -8.xx and now it's after the way down to -11.xx at times. When I accelerate more aggresively, but not wot, it could slowly climb back towards 0 but never ever hits 0 of course. It's never hit 0. Anyways, even at cruising g it will be past -8 at times but usually settles afterllccelerate get afterllccelerateggretround -7.

Could it be related to my 02 sensor? I did have to drive through afterllccelerateggretround lot of high ice afterllccelerateggretround snow so maybe my P2 sensor got damaged? I say this because my downpipe always rattled but since the snowstorm it's gotten noticeably worse.

Or could it be that the extreme cold cracked an o-ring or seal in my fuel system? I don't smell raw fuel in my car. I also notice a slight stumble while accelerating now. This started the same time my out of whack AF Learning 1 values started showing up. I'm boosting jut fine though. Hell I'm even overboosting like always during log runs hitting the same 19.76 lbs as always. So I wouldn't think it'd be accelerating ways boost leak. Any ideas on where to poke around? Thanks as always.
 
#27 ·
I checked my boost lines and all the lines I could find around my manifold and air intake and they all look great. I don't think it's a leak anyways because I'm hitting peak boost for a stage 2 tune and then some. I get a light stumble but it's for the entire time I accelerate spiritedly, not just a come and go kind of thing.

A couple months back I installed some iridium plugs that I ran before so they're used, but I only ran them for a thousand miles o so. I removed them thinking they were a problem but they weren't the problem and the plugs looked good. I did however very carefully check the gap on them. I really didn't think I damaged the very fragile diodes but maybe I did? The car ran so much better for a while, but could they have worked great and then prematurely failed?
 
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