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Discussion Starter #1 (Edited)
Help me please

hi all!
ok heres my problem

car and mods:
99' 2.5 RS coupe @ 44k miles
PRM Ganzflow intake
Bruillen Full Header back exaust and hi-flow cat
JUN flywheel
ACT clutch
Denso Iridium plugs, stock wires

ok heres the problem:
the car was running AWESOME after i had the intake and headers/ exaust on. No CELs nothing, and i was beating my friends Probe GT with Mazda KLZE motor swap. I would spank him off the line and he wouldnt catch up to me untill around 90-100 mph. (it redlines at 8k)
then i got the car back after the flywheel and clutch were installed (this was months ago bear in mind)
and the car was misfireing HORRIBLY off the line. The car would literally rock back and forth violently. I drove the car like this not knowing what was wrong for like 4-5 weeks. Turns out it was the Bosh Platnum +4s i had on the car for less than 10k miles. the solenoid on (i think) plug for #1 cylynder was burnt off. so i changed them with some regular NGKs and the car ran fine again, however the car had lost a lot of power. Im talking not being able to keep up with the probe at all after 1st gear was done.
went on i-club and everyone said it was probably the 02 sensors, and by that time i had gotten a CEL. took it to autozone and it was the o2 sensors. since that time ive had them both replaced with aftermarket BOCSH sensors to save money. heh took it for a ride and there was a small gain in power, but still wasnt as fast as it used to be before everything started going wrong. i race a bunch of friends often and people that i used to beat or keep up with were spanking me. The car drives fine, felt fast, and i could only see the power loss when racing my buddies. couple weeks later, CEL for both o2 sensors again. Also, the car was idleing weird, hopping from just over 100 rpm (causing the headlights to dim) to about 800-900 rpm range. once warm, the idle wouldnt change as much,(maybe 400-500back and forth) but you can still hear the exaust note raising and lowering, lights dimming and coming back to life. I took the car to the same mechanic who had installed the flywheel, clutch, and the o2 sensors that were causing the CEL. He said that the car was running super rich, and that i might have burned out my cat because of it. So i tell him that its probably because i have an aftermarket intake and they are known to make the car run rich. Get home, start looking for an Apexi S-AFC so i can lean it out. what do i find out? that aftermarket intakes on 99s cause the car to run LEAN! the exact opposite of what i thought was causing the problem.
ok so what the hell is going on? why is my car running rich and getting bad MPG when its supposed to be running lean?

MAF blown? i never got it replaced for the recall.
could i have messed something up internally by driving the car for so long with a misfireing plug?

this is what im going to do after i get the S-AFC installed and tuned if the power doesnt come back
im gona get new Subaru o2 sensor front and rear, MAF from subaru, and new cat (if its fried)
think that will help? any input greatly appreciated
 

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it was probably running rich and misfired, but it should be alright. which intake did you say you had. if it keeps the upper plenum above the throttle body then you didnt need the afc. if not and its a j-bend style then you need to only add fuel at 5grand and up. did you do the blue wire mod to check you airfuel? my99 setting were 5-10%51/2-30, and 6-61/2 were also 30%. sounds high but the car runs a decent a/f ratio. my mods are weapon intake, borla headers and apex n-1. plus did you reset your computer? i wouldnt replace everything, i would make sure that the o2 sensors were the correct #s and would check to see if you melted the cat. that could be why your car is struggling. and just get some ngk plugs, wires. hope this helps and sorry for the paragraph
 

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Discussion Starter #3
that paragraph was awesome. you obviously know a lot more than me, and i will search for the blue wire thing and check things out. also, i do think its the cat b/c it smells really bad in my car right now. Anyway, thanks alot and ill check back after try those things.
 

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Re: Help me please

MoBucks said:

Also, the car was idleing weird, hopping from just over 100 rpm (causing the headlights to dim) to about 800-900 rpm range. once warm, the idle wouldnt change as much,(maybe 400-500back and forth) but you can still hear the exaust note raising and lowering, lights dimming and coming back to life.
i am having this same problem, but only on cold starts, and at time the car will run up to 2-3k at idle... but only on a cold start after a couple of days...

i did the throttle body mod and thought this might be it, but it can't be as the coolant wouldn't be warm yet to help start anyways...

it's just plum strange...

as far as the maf replacement... it seems to me like it was a waste of time... driving home from the dealership the CEL that the darn thing was supposed to fix went off again... it does it both with the Cobb and stock intakes...

i guess i'm gonna have to take it to the shop although i hate to...:curse:
 

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that smell is probably from the exhaust. it could be from the mandrel bender for the pipes. i believe they run some kind of oil as a lubricant. or it could be a sticker that was on one of the pipes or just something that melted on one of the pipes.
 
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