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I've searched but to no avail. help me out please.

I bought the HP racing header with cat and i'm experiencing some lagging. Let me explain:

After installing the header, which was super difficult, I connected the o2 sensors without the o2 sims that they provide. I was dumb and didn't know what they were for, and it was late. Regardless, the header hit against the front frame of the car and would vibrate when i braked or when the engine moved forward. So, I removed about a 1/4 inch of frame, melted it off with a torch, where it hit; no biggie.

Vibrating solved. When I drove the car things were fine, no lagging at all, but then after a day the engine light came on. So I call HP and ask them what the little boxes with wires are for and why they are needed. I find out they are o2 sims and trick the engine, and without them my car will lag.
So, i install them according to their directions, but the directions don't say which white wire to connect the o2 sim to since there are two white wires coming from the o2 sensor. So, i connected it. Reset ECU. But know after three days of driving, including freeway driving, the car lags. It seems as if it is not getting enough gas.

I call HP and tell them. Damien, the guy at HP, tells me that I might need a Super AFC fuel 'something or other' in order to opent the fuel line more and for longer.

I decide to give it another day or two, thinking that maybe the ecu is dumb and that it'll adjust to the new extraneous amount of exhuast. Today, the engine light came on!!

Help. Logically, it must be the o2 sims because it was not lagging before i put them on.

Anyone experience this? Did i install the o2 sims wrong?

Also, the header had two locations on the primary tubes for o2 sensors and a third on the "cat" itself. HP said you should plug one. DUH!!! but they don't provide that, and Damien said that a spark plug works. I can't believe they don't provide something to plug the second 02 sensor location on the header

 
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bump.

 
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I'm suposed to get my HP Racing Header w/ HighFlow Cat today and damn u got me all worried already......man let me know if u solve ur problem......I'll keep checking for new replys!

 
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i think you might have put you o2 sim on wrong.i have the same problem it hapened when i cleaned out my cat and put on the o2 sim but my light never came back on. I have obx hp stile header.some times when i step on it the rpms go up but it seems like the car isnt going nowhere. after a few days of running like that when i let the rpm go to 6 it backfires. can you put your stock cat on? and see if the lagin goes away goes away. i bought an oem cat from another member im just wayting till it arives to try and see if its the cat.if so ther still must be a bad signal going to the ecu. for a plug go to the auto part store and get an oil pan plug i dont remember the size but i think its an 18mm plug. thats what i got and it works. looks much better than a sparkplug

 
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I think first I'll reevaluate how the o2 sims and sensors are connected. If that solves it then great. If not, then i'll consider removing the 'cat' and reinstalling the stock cat. Although, i might take it to get tested. An obdii test or dyno would work. the guy at HP said to get it dyno'd.

 
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once you get the sim on wright the obdII will not read a signal i know i have one but i think the sim just tricks the obdII and still sends a bad sig to the comp. let me know what you get on the dyno.

 
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How important is it to have the o2 sims on? Logically, if they didn't make it lag before, but since they've gone on the car lags, taking them off would seem the rational answer.

 
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withought the sim your engine light comes on and if you need an emission test where you live it wont pass. putting one on my car made the engine light go off and the obdII doesnt read a bad signal. but the car still ran like crap like you sayed its like it doesn get the right amount of fuel. but every time i reset the comp it runs ok for like 15mile then it starts to lag.

 
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HP is making me frusturated. Why would they produce a header for a 01+ civic that lags? It doesn't seem logical.
If I removed the o2 sims the ecu could adjust to the amount of exhaust, no? The engine light will come on but i can deal with that. And, being that my car is registered in AZ i don't have to worry about tests.
I will tell you that my exhaust now is nasty. It emits a crap load of exhaust. oh well- that's the price to pay for a little more humpphh.

 
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Would the ECU adjust to the amount of exhaust being produced by the header? The check engie light would come on, but do i really need to worry about that? And are the 02 sims that important?

 
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bump

 
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HP also has directions using the colored wires in the rear o2 harness, which are all their own color. Use those to make sure you are wired in correcty for the o2 Sim.

Aye, it is a shame about the extra bung, but you could keep the factory o2s up front and put a wideband sensor into the rear bung. I just plugged it with an extra o2 sensor I had laying around. Having lots of broken cars has it's advantages

 
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Have fun installing it. Go in from the bottom. I don't know if it will be the same as mine but i had to remove the motor mount and bend those mounts in order to get the header in place. Bending the motor mount back isn't too hard if you have the car up on a lift.

 
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"So, i install them according to their directions, but the directions don't say which white wire to connect the o2 sim to since there are two white wires coming from the o2 sensor. So, i connected it. Reset ECU. But know after three days of driving, including freeway driving, the car lags. It seems as if it is not getting enough gas."

so uh... try switching the wires. come on now

 
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and yes, the ECU is suppoed to re-adjust itself if something is being altered with the flow, exhaust or fuel pressure if i am correct. this taking a certain amount of time though, you should still NOT see any lag..... PERIOD. when you install headers.

rationally, bigger pipes=more flow. and more flow=more HP. so if you are lagging, then DOH! its your sensor. keep the thing on and check ur wires like i said above, maybe you used the wrong white wire.

 
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You're right-

though, I think i'd have a bigger problem if i tried to install more than one header on my car.

but, i was going to re-work the wires tonight.

 
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my exhaust is also nasty

 
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rework the wires and then all you are going to notice is the engine light wont come on any more trust me i have ran my car like this for a wile. my vic actually ran good with just the header i regret gutting out my cat it just made it slower.

 
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i had the hp header/cat/downpipe and was so frustrated with it. i ended up just buying a obx shorty header and a megan downpipe. with this set up i have no 02 sim. and no check engine light. my car also seems to be more responsive with this set up that with the hp set up.

 
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you'all have EX's ?

 
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yes i have EX. i also have obx shorty(hp style) but i have a gutted out oem cat with o2 sim

 
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man I got a LX.....and my header from HP is coming on wednesday...I'm wondering if I'm gonna have the same problems......!!!!!cuz I think OBX and HP are the onlyones that makes them for my car! should I return that one and wait on the OBX (out of Stock).....and I been having problems with my cat.. it goes on the header!

 
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yes, i have an EX too.

 
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i've got an EX as well

 
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What did you do with the cat? did you replace it with something else, reinstall the stock?

 
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hey i have my hp racing header for like 1 month and i had the same problem with
1 pipe that came against the frame but no big deal!installed everything except the
o2 sensor module. and idd the engine light went on after a day,i reset the ecu and tryed again!so i want back on after a day.I kept driving and it went of after a few day.
So i posted on honda-tech my question considdering the o2 module and
the only thing its does is that its fools the ecu and makes it believe
that your cat is working.
and i have no problem with the engine light and i dont have the module installed.

grtz

 
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in place of the cat i have the megan downpipe.

 
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So then you haven't had any lagging problems, huh?

 
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I had my hp header and cat for like 1 year and a half now. And nothing is wrong. I have it on a LX.

 
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I took off the sims completely last night and the lagging stopped. But, Truehonda said my car would run lean without the sims. Anyone have the sims installed?