I've got a 98 JDM Forestor STB so it's a ej20t, it recently been giving me some headachs. It started a few day's ago, on the way home, it felt like it was running on 3 cylinders and a WHOLE LOTTA black smoke was coming out of the exaust. then when I started it up after to go out, no prob. that night. Next day to work no prob. on the way back same thing. So I go and change Plugs, alway's using platnums, wires, fuel filter, oil change and are filter. I through in an injector cleaner for good measure (not the Stp stuff, something from my mechanic, cant remember the name right now). Now the car idles' smoother and stuff, BUT, it feels weak! doesn't feel like the 250hp it did before, feels like a regular car! when you stomp on it, ok still more power then regular cars, but it's not what it was! AND to top it off it did that 3cylinder thing and lots of smoke!? Anyone have any ideal what it could be???

 

Clean the throttle body and seafoam it. Check the coil packs?

 

cleaned the throttle body, nothing! Any ideal what coil packs will cost me??

 

did you do a compression test? how were the plugs that you changed out? check your coil packs as stated

Jon

 

I can't remember exactly how much coil packs are but they run more than 100 each...

 

Gonna try and get compression test down this weekend, not looking forward to it for 2 reason's: 1) what a ***** to get to and 2) the obvious fear of in need of an overhaul!!! but if anyone else can suggest anything else, I'll post results.