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SIR lost power...Need HELP!

600 Views 8 Replies 3 Participants Last post by  jayb16a
Hey guys, I've got some major problems and need your help.

I've started mod'n my '99 SIR b16a2 and have reacently noticed some big power losses!! I've added a AEM cold air intake, Vibrant performance cat-back and a DC sports 4-1 ceramic headers.

Before I added the headers thing we're go'n great but now I'm slower than before and I belive that I'm running rich!! I even got beat by my brother's non-modded 1991 integra... what the !#$& !!

Just to rule some problems out I've done a compression test to make sure I didn't blow a ring but I'm running 180psi accross all cylinders which I belive is what it should be at!

I do have a lot of weight in my trunk which is filled with around 200 lbs of sound system but it still does not explain the power loss. Please help!!!

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wieght is a big factor with Civic's. You've probably noticed how much slower your car is when you get another person in there. Did you have all that wieght before you noticed your power loss???
Hey Benny, thanks for the reply.

I had the system in with the intake and exhaust and things were fine. It was only when I added the headers that I noticed a prob but it just does not make sense! I orginally had a DC Sports 4-1 header off of a GSR on my ride and swapped them for the SIR model 4-1 from DC Sports. The GSR headers made power but the SIR's lost big time.

I've also been getting some back-fire! As it stands right now I'm a little lost and short on "change". I was concidering a v-afc to be able to see better what the engine is doing and to be able to adjust it, but right now things are a mess!

I've recently purchaced a stock flywheel to be lightend, but now I'm holding off until this prob is fixed. If you have any ideas on what the prob might be and any future mod's that might help, please let me know. I'm at a loss!

Thanks, Jay
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a vafc is a nice unit but maybe you should take it to honda and get them to check it out before you drop $350. I mean i have DC 4-1 aswell with Greddy evo and AEM CAI, and i have had no problems. so its either got to be you fuel or something else. Have you ever reset your ECU??? If not just pull the neg batterie post off for a couple minutes than put it back on and let it run for 5 minutes. maybe that will solve your problems.
As far as I know, backfiring is caused by a leaking exhaust system. I can only suggest checking gaskets and/or replacing.

Are the O2 sensors connected properly? I could imagine A/F mixture going way off if they were not in there.

Good luck man!
if the O2 sensors went connected right the check engine light would come on.
Hey Benny,

I just got a reply from another form and now reallize that I did not allow the car to idle long enough before I tolk it out on the road. I'm going to properly reset the ecu tomorrow and let you guys know how that turns out, but I still think there may be more problems than just that.

Thanks for the help, Jay
Hi BlackEG_Si,

when we put in the headers we did have a problem with removing and re-installing the O2 sensors. I'll have a second look but everything seemed to be o.k. but I think benny might be right. If there is a prob with the 02's a warring light should come on.

Thanks for the input, Jay
Hey guys,

sorry it took so long to get back. Well I found the prob and all of the lost power has returned plus about 5hp more!!! As it turns out I have never propperly reset the ecu. As it turns out I had never dis-connected my 1frad cap which is hooked up to my system everytime I had attemped to reset the ecu. So when I was dis-connecting the neg off of the battry, the cap had enough power to keep the ecu from resetting!

The reason for me noticing the drop off in power when I changed the header seems to be because they are further from stock in spec than the previous ones I had installed.

I do beleive however, that if I'm to enjoy the full potenial of the headers I'll have to change my cat, but till then at least I regained what I had lost.

Thanks for the help,
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