civic d15b jdm

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So i have posted a few things on here in the past few days.
Built a 95 civic with d15b jdm motor.
Have cold air intake and full exhaust including header. 2 1/4 inch header to 2 1/2 inch cat back.
p28 and i wired the 4 wire o2 in myself. got it right on the first time.
have the purge sol. plugged in and capped off since i chose to keep stock d15b intake plenum and head.

the car runs great and roars down the road. Here is the issue. I am running way too rich. I have read that the p28 and this motor will work but run rich. I have also read that with intake and exhaust i should have bumped the air up enough for a proper a/f ratio.
car also runs extremely cool and i think this is due to how rich it is running. i even put in a new thermo because of it.

any thoughts on how i can fix my issue?

I do have a p06 as well as my p28.
Since my p28 works i thought it might be a better idea to go ahead and mod the p06 to vtec and chip if that is my only option since this is my daily driver and have no other mode of transportation to get paid. gotta keep her running.

Help me get better that 24 mpg please.
A intake or exhaust would not lean out the air/fuel mixture; as compensation parameters are fixed(ie, load and sensor input during closed loop or straight off the maps during open loop). Only way to lean it out is modify the fuel pressure (which I do not recommend), or chipping the ECU with a P08 map.

BTW, I got ~57mpg with a JDM D15B VTEC running a P28 ECU....sitting around 3700-4000rpm(roughly around 65-70mph) on the highway. ;)
I agree with the above posts....get a P08 map if you cant get a will eleviate a lot of frustration.....your gonna pay for it in fuel in no time...
i am paying for it in fuel. i did a fuel check this last fill up to see exactly what mpg i am getting (9.89 gal. for 211.1 miles) 21.3 mpg. not too good since i was supposed to get this car for a family economy car. is it a pain to convert a p06 to vtec+chip? i have a good p28 that i know runs my car now so.......dont wana mess with what is working.. thanks in advance.
You can chip the P28 and not have to worry about converting the P06 to VTEC. When the ECU is socketed/chipped, there's usually a removeable jumper installed and simply removing the jumper will revert it to a stock P28 map.

I want to say there's something else wrong with the motor. That mileage is horrible for a D15.
i just dont quite know where to start. i have a spare pressure regulator that i might try on for size just in case mine is bad or something.i also have spare injectors from y d15b7 outa the car in the first place. whatcha think?
As what almost everybody said so far, I would get your p28 chipped with the p08 map so its running with what its originally meant to run with and then take it from there if you still have problems. It isnt as much of a pain as you may think.
I run just fine with a P28 hehe 39mpg till 4,800 RPM's then ouch! lmao... Man ya should shift out of 1st and 2nd once in awhile mite get better mpg's lol
so i am an idiot. i pulled the codes and it says o2 sensor. when i installed the o2 i put it in the bottom hole of my header. i have an issue with the top one because i have a plug in it that wont come out. will it make a difference?
I would think so, because of were its getting its readings from. I run my D15B w/o an o2 sensor just fine
As long as it's not leaking, just leave it in there as a plug. It should work fine.
okay so it makes no difference if it is in the top one or bottom one? thats the only code i got out of it so i am back to who the heck knows why i'm at 21 mpg. any suggestions?
If it was a stock 1-wire O2, upper would be recommended but since it is a heated(I'm assuming) O2 sensor than the lower part should be fine.

How were you able to check so quickly/how are you measuring? Also, does it feel like you have to give it a lot of throttle to cruise?
it is a heated one. i know i have it connected right since my car will run and not just die after warming up and the code given is not the one for the heater circuit. it gives me an oxygen sensor error code. not too rich code or too lean code but just o2 error code. what do i do. or at least where do i start?
sorry 3000 rpm going 65 mph aprox 22 miles one way almost all freeway. still getting 21mpg. i am gonna build my p06 to a p08 through xenocron.