hey guys and happy thanks giving. i have one question.every time i hit about 120mph i dont do it often my car does a sudden jerk and me cel turn on.once its on if i go that fast again it wont jerk.i dont know what the code it but it doesnt affect my cars perforformce. i clear by disconnecting the battery and wont come on unless i go 120mph again.i have a catless turbo if that has anything to do with it. let me know what u think thanks.

 

sorry i mean catless turbo back exhaust with cel fix

 

again sorry its an 05 sti

 

get teh code pulled at autozone

 

is the MIL flashing or is it a solid light

its prolly nuttin to wory bout if u said it runs fine. same thing happened when me and a friend were in his impreza, heard a loud pop, the car kinda studdered, threw a code. it ended up being he blew a gasket on the DP so all this extra air was gettin in @_@~

 

the cel is solid light but the cruise light flashes

 

that makes teh rear 02 go crazy gosu

 

do you have a turbo back exhaust installed? might be the O2 sensor if it is.

if you know anyone w/ an accessport they can give the cel code so you can look it up.

 

i get a check engine once in a while too but it goes away after a while or something or I just disconnect the battery.

 

If it's a 05 sti with turboback ex, you need to get ur wg ported and then have it tuned. Its boostcreep.

 

sounds like boostcreep or fuel cut

 

i dont think its boost creep because i dont have a bell mouth downpipe i got the hks. i look at my boost gauge its about 15psi. but it does feel like fuel cut like it has a govenor is there anyway to fix that if it is fuel cut

 

it is a fuel cut due to boost creep. get an engine management and you will be fine.

Ferdie

 

i say somehting simple or crazy

 

I would venture to say it is the downpipe is causing it. The bell mouth changes the dynamics of the exhaust. This effects the wastegate duty cycle. I would guess that your boost pressure @120 mph should be lower than 15psi (depending where you are on engine loads). but because the dutycycle has changed the FBC cannot adjust anymore (this is not a FBC problem). The ECU thinks the boost is out of control and cuts or restricts the fuel hence cutting boost. What you see on your guage verses what the ecu is suppose to see at that speed is two different things. If the ecu sees that the boost too high it will try to adjust. If it cannot compensate for it then it will make take precausionary measures (flashing light).

This is a problem with the STi and changing it's exhaust, the turbo is at its limits and any changes throws things off.

The janitor.