[lamers24]

Hi guys i bought a 02 wrx about 2 months ago and it has a bad sputter and flashing check engine light at high rpm only with the electronic boost controller on. I have replaced the plugs twice and properly gapped them just to be sure. The mass air flow sensor and fuel filter were also just replaced. The car also had a custom dyno tune done. I did recently discover that the car also does have a manual boost controller under the hood so i turned it all the way down with the problem still persisting and im wondering if the vaccuum lines would be wrong having the manual and electronic boost controllers both installed.by the way the car also has a aem intake and full injen ses exauast. If both boost controllers are turned off all the way the car runs like it normally should with no problems.

 

[SD_GR]

Search "fuel cut."

 

[MainFrame]

At what boost pressure does it start cutting out?



I had a similar problem that took about two years to diagnose.. in the end new coil packs along with cleaning every ground in the engine bay fixed it.

 

[lamers24]

it seems to be around 10 psi and above

 

[mycologist]

Can you get any specifics about how it was tuned? If it properly done, a hybrid boost control setup with the MBC and EBC is the best you can get.

new hybrid mbc/ebc method of boost control - NASIOC

What are all the CEL codes it has stored?

 

[lamers24]

it wasnt any kind of hybrid tune neither me or the tuner at knew about it at the time. I had it tuned 2 weeks after buying the car after hearing horror stories of the ebc and no tune to go with it.

and i havent got a chance to check codes yet hopefully by the end of the weekend i will have some

 

[mycologist]

Kind of unbelievable he wouldn't notice that. I'd be wanting a refund, or if you still trust him at all a free retune.

 

[lamers24]

checking for boost leaks today and noticed i had a leaky valve cover gasket would this have anything to do with the problem?

 

[mycologist]

You really need to start at this by posting the CEL codes as I asked. Get them read ASAP as that is much more useful information than what you are working with / providing.

The valve cover gasket - no I don't think so. Although I don't think you should have had too much pressure in there if your intake valves were closed for the test and the oil filler cap removed. I'm not really sure about that but I think it would have to come past the rings or valve seals? I wonder if your motor is running low compression now.

 

[lamers24]

thanks for the fast reply i will get the codes read and get the mbc changed out hopefully by wensday

 

[lamers24]

went and got the codes scanned today and they came back
po546 - exhaust gas temature sensor circuit high bank 1
po483 - cooling fan rationality check

 

[mycologist]

Po546 - that is a bad or missing EGT sensor in the uppipe. Is the uppipe stock? If it has a cat in it you should replace the sensor. If it has no cat you should remove the sensor if it is there so it doesn't send pieces into the turbo. Plug the whole with a bung plug. Then disable the CEL in the tune (if you have no cat your tuner should have done this).

You need to find another tuner. I'd recommend pulling the MBC completely and run the stock boost control system, with the correct ID tubing, restrictor pill, and t fitting, but I have no idea how it is going to react (possibly overboost badly) with the map you currently have on.

 

[mycologist]

po483 - Your car decided it was hot and qued the fans. After a certain time the temp. did not go down. Make sure your radiator fan system is working correctly. Also check that their is airflow through the radiator and no air bubbles in the cooling system etc.

When you get both of these issues addressed, I think your car will come out of limp mode.

 

[lamers24]

there is no cat and the car does have a egt gauge which does funtion properly and the new vacuum lines and pill will be in thursday thanks for all the help so far

 

[lamers24]

so i put the pill in and rerouted the lines and that seemed to fix the sputtering problem but im still getting the flashing cel at around 4k and the car seems to hesitate a bit then continues on fine through the rest of the gear and also like you said the car seems to be overboosting on this map now

 

[mycologist]

What do you mean by it has a working EGT gauge? An aftermarket gauge has nothing to do with the issue - You need to have that CEL cleared and if your sensor (not gauge) is still in the UP without a cat it needs to be removed. You can disable the CEL in the map (or your tuner) or you can do the resistor mod.

What is going on with the other CEL regarding the radiator fans?

You need a correct tune for the boost control system without the MBC. Do you have a DP? If not you can use a stage I map or the stock map, if so try a stage II map, or go get it retuned correctly. What kind of EBCS do you mean it has (do you mean the stock boost control solenoid)? If you have like a grimmspeed EBCS that takes a different map/tune.

These are all things that have to be taken care of ASAP - it may or may not completely fix your issue but we won't know until you get caught up.

 

[lamers24]

there is no cel light on when the car is running the only time i get it is around 4-5k and it will flash 3 times and go off and when i go to check the codes theres nothing there. and it has a blitz ebc. i will hopefully be ordering the cobb accessport shortly and going to go stage 2 tune but until then i will just stay out of boost as much as possible

 

[mycologist]

Consider just getting a tactrix cable and doing an internet tune like XPT - it will be better and cheaper.

Remove the Blitz thing and sell it. If you want an EBCS get a grimmspeed and get a correct map for it. I thought you meant the stock BCS this whole time. You can see if that makes things better temporarily, or if you are still overboosting just run the line from the compressor housing straight to the wastegate actuator - that will limit you to around 8-9 psi until you get a tune or a map, and should be much safer.

 

[lamers24]

well i was doing some more digging and just found that there is a turbo xs utec in the car so now im kinda lost once again. how i missed something this big i have no idea

 

[mycologist]

UTEC is a good piece, but harder to find a tuner compared to Cobb and Opensource. You could just keep that and the other pieces and get a protune - let them decide if they want to use the MBC etc.