Hey guys, i have a problem. I own a 90 Civic Si with a zc, i want to take my **** dc headers off and roll with the stock cast manifold. I tried putting on the manifold that came with the motor but dont know which downpipe to use.

I tried a complete integra manifold but the bottom pipe wont line up with the exhaust piping.

Would a stock civic hatch or crx complete exhaust manifold and downpipe work?

And for the ones that want to know why i want to go with the cast manifold instead of the headers... The fact that the O2 sensor sits so far back on the headers make it take forever to heat up and send the computer into closed loop. My car is running way too long on open loop and killing my gas mileage. Running it up font will heat the sensor up a lot quicker and make my mpg go up.

The little bit of performance that those crappy dc headers free up is not worth the gas im blowing because its at $3.54 A GALLON!!!!!

Thanks for the help guys.

 

you can use the stock Si exhaust manifold, downpipe, etc. <U>or</U> you can use the stock ZC manifold with 92-95 EX downpipe - i would use the Si, since it all bolts right up - the Si ports don't match the ports in the head exactly, but we have seen many of the ZCs with the stock Si manifold and they seem to run just as well without matching the ports as they do with it port matched

 

i didnt know a header would decrease your gas mileage.


might be your right foot.

 

DOHC ZC use alot more gas then stock engines man, you should know that. And 3.54$ a gallon? I'd kill for that, you can pay my 1.14$ a liter.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by STREETWERKZ &raquo;</TD></TR><TR><TD CLASS="quote">i didnt know a header would decrease your gas mileage.


might be your right foot. </TD></TR></TABLE>

I know the zc uses more fuel and all and that the header is just a header but since my O2 sensor is not heated like obd1 sensors and sits so far back on the header, it takes too long to heat up and send the ecu into closed loop.

I took it to school and the instructor and I drove around with a fluke scope hooked up and noticed that the O2 sensor was taking too long to heat up and begin communicating with the computer and closing the loop. So when the car is running on open loop, it isnt adjusting the fuel ratio, so its running rich, meaning i am wasting more gas than if i had the sensor heat up quickly.

I would normally not bitch about this but i am a merchandiser for kelloggs and i drive around all day and still drive up to school everyday so this is really killing me.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 90_EF_Si &raquo;</TD></TR><TR><TD CLASS="quote">

I know the zc uses more fuel and all and that the header is just a header but since my O2 sensor is not heated like obd1 sensors and sits so far back on the header, it takes too long to heat up and send the ecu into closed loop.

I took it to school and the instructor and I drove around with a fluke scope hooked up and noticed that the O2 sensor was taking too long to heat up and begin communicating with the computer and closing the loop. So when the car is running on open loop, it isnt adjusting the fuel ratio, so its running rich, meaning i am wasting more gas than if i had the sensor heat up quickly.

I would normally not bitch about this but i am a merchandiser for kelloggs and i drive around all day and still drive up to school everyday so this is really killing me. </TD></TR></TABLE>




that does make sense.

 

3.54 a gallon o god damn! shyt down in austin.tx shyt only $2.40 up to 2.85 a gallon

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by aus_tex_crx &raquo;</TD></TR><TR><TD CLASS="quote">3.54 a gallon o god damn! shyt down in austin.tx shyt only $2.40 up to 2.85 a gallon </TD></TR></TABLE>

Yeah! its a bitch, but its better than when i was driving an 03 silverado, its only the 4.8L V8, but it was enough to drain the wallet very quickly.

Thanks again to jlicrx for the help. he gave me a few ideas.

 

I get 35-40 mpg city with my dx transmission. no joke.