richtypera

Hello all.
my mate has an 03 wrx all he has done is headers and dumpvalve.
today he fitted an air filter and the metal pipe which you screw the air flow meter into (which is sealed properly).

when he did this the boost droped from .8 of a bar to .5 of a bar.

he then thought he had a problem so put the standard box back on and has know put the engine managment on.

can someone please help is the boost drop normal and why would the engine managment light come on when he put it back to standard thanks

richtypera

anyone.

woody1980

has it gone back to completely standard? no mods to maf sensor and you have made sure that all pipes are clear no blocking and all put back in place?

the turbo solinoid is connected to the air filter intake. if this is blocked in anyway or restricted air flow then ecu will think engine isnt getting enough cold air and not put boost as high.

richtypera

hello mate all pipes are clear and fine. i hve also disconected the boost solonoid pipes to the turbo and put a stright pipe from the turbo to the actuator. no difference it was still .5 bar.

now its all standard again the boost is back to .8 of a bar but the engine managment light is on.

woody1980

i take it you havent ben mucking around reseting your ecu then? car runs ok yeah, just the light is on?

you could try an ecu reset and it will tell you the error code for what te problem is.

richtypera

bin reading up and it says on here that you cant do an ecu reset on here without pluging it in properly. not like the older style scoobs

Jolly Green Monster

iTrader: (4)

you will have altered the maf voltage the ecu sees, therefore altering the load calculation and therefore running lower in the fuel and ignition tables, ie. more advanced and leaner as the ecu cannot see the true load the engine is under..
the boost will have dropped as a safey precaution by the ecu.. it is probably detting it's t*ts off.

it needs mapping with that air intake fitted.

The CEL could be a retained error code from the air intake change or presuming it is decatted a cat inefficency code.
Try disconnecting the battery overnight.. or it needs resetting via laptop or select monitor.

Simon

richtypera

i have sorted the engine managment light. so just the drop in boost.
jolly green monster why would puting the air filter on make the ecu shut down. i know of a few cars that didnt get it mapped after putting an air filter on. is there something were doing wrong. is that the ecu tek map that you would do to sort it.
thanks

Jolly Green Monster

iTrader: (4)

the ecu uses the maf sensor to know how much air is entering the engine..
by altering the tube it is in it will under read if the tube is larger or smoother etc.. it would over read if you put it in a smaller diameter. Therefore the ecu will inject the wrong amount of fuel and run the wrong timing causing dettonation/knock..

The ecu uses an advance multiplier (AM).. all running perfect on the 03 ecu it will be running at 16.. if it picks up excessive noise ie. det, knock, pinking it will reduce the AM.. this will mean it will run less timing.. when it gets to an AM of 4 iirc it will reduce the boost.

Yes an EcuTek remap would sort it..

however you are now saying to have no CEL and reduced boost? whcih with the standard intake back on you should be able to sort.

Simon