I have a 2002 Subaru WRX, with an HKS Carbon-Ti Exhaust, SSQV Blow off valve, Invidia Up and Down Pipe, Injen cold air intake. When I had all my stuff on it before the up and down pipe, it ran great. When I put on my up and down pipe, it really started to run like crap. First off, when I put it all on, my buddy stripped out the EGT sensor, and he said it was an O2 sensor and I looked up how much the O2 sensors were and they were like $200. I didnt have the money at the time so i just left it with no sensor it (exhaust leak big time) then I got the idea to just buy a bolt and plug it up, until i get the money to buy a sensor. Well by the time i found out that it was the EGT sensor my car is all ready running like crap, I put the sensor in...still nothing. Then i found out that i needed new spark plugs, no big deal i got one step colder plugs put those in...still nothing. When i start up the car it doesnt have a steady idle, it goes up and down, and it seems to be miss firing alot. Everytime i go down the road it backfires. If anyone has advice on how to fix my Rex, it would be greatly appreciated. I was thinking maybe its my fuel injectors? and maybe I need a new fuel pump because I have bolt-ons? Thanks Guys

 

You don't need to do anything to your fuel system with what you've installed. In my opinion it wasn't smart at all to run with a missing sensor...and you may be reaping the consequences. Hope your motor is ok. I know most people call this the scape goat, but have you tried resetting your ECU? You can do this by disconnecting the battery and pumping the brakes a few times to discharge any power left in the system. Are you running without engine management?

 

No nothing, i want the cobb accessport but i dont have anything done to the ECU

 

Have you tried resetting the ECU?

 

How would i go about doing that? just like he said disconnect the battery and pumping the brakes? or going somewhere and having it done

 

Dude, I told you how to do it lol. Disconnect your battery, ie take off the black ground wire, and then pump the brakes a few times to discharge any power left in the system. This is going to take the power from your ECU so when u start your car, it will re learn. It might take a bit longer than usual to start your car the first time after you reset it. Anyway, you will know if you did things right because your clock will be reset etc. Hope that helps.

 

how do you know its misfiring? did u pull the code? the reason ur car is backfiring is because your bov dumps to the atmosphere instead of back into the intake. the crappy idle could also be from a leak around the bov. i also highly reccomend getting engine management.

 

I once forgot to tight the 2 bolts on my factory BOV and my idle was going up and down just like you said. When I tapped the gas it would backfire. You also definitely need to replace that missing sensor ASAP! Your killing your car man!

 

get an ecu big time. that shouldbe been one of the first upgrades. the stock ecu can only handle so much. and its backfiring cause youve got too much fuel in there, not cause its misfiring. reseting the ecu will only do so much. if you replace the ecu then you wont need to replace the egt sensor, just do the resistor mod. if you were in TX, id give you mine. not using it. good luck. fyi: i also have a SSQ BOV and ive never had idle problems, before or after the ecu install, and i dont backfire.