I'm using a chipped p28 on my jdm b16 and my gas mileage sucks. I set my fuel at 38psi and a full cx gas tank only last me barely 200 highway miles. I know the performance would suck using the stock cx ecu, but would it hurt my motor in the long run if I switch back and fourth my chipped p28 on the weekends?

 

chipping an ECU wont give you more power. using a CX ECU on a B16 wont increase your gas mileage. blindly increasing fuel pressure w/out measuring the AF ratio on a dyno will not increase your power.

there i think i cleared up your confusion.

 

You are relying on the fuel gauge to measure fuel economy is not very accurate. The fuel gauge rarely indicates correctly. Fill up and reset the trip meter drive till the tank indicates 1/4 tank or less. Fill back up record the number of gallons to refill the tank and the mailes on the trip meter. Divide the gallons into the miles Miles/gallons = MPG miles per gallon. I do not have a B16 but my zc averages 30-34 MPG accoring to how much i get on it.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tpr &raquo;</TD></TR><TR><TD CLASS="quote">You are relying on the fuel gauge to measure fuel economy is not very accurate. The fuel gauge rarely indicates correctly. Fill up and reset the trip meter drive till the tank indicates 1/4 tank or less. Fill back up record the number of gallons to refill the tank and the mailes on the trip meter. Divide the gallons into the miles Miles/gallons = MPG miles per gallon. I do not have a B16 but my zc averages 30-34 MPG accoring to how much i get on it.</TD></TR></TABLE>

cool. I'll try it tonite

 

I already replace my o2 sensor. What else should I look for?

 

Are your plugs really black . The program the ecu is running might be running it really rich most of the time or in low rpms. My chipped ecu runs really rich at idle and lower rpms. You might also have an o2 sensor going out or bad. A bad o2 will automaticly run richer. You should also get a vafc and get ahold of a wideband or at least someone who owns one and hook it up. That alone will tell you whats going on.

Whoops didnt see that the o2 was replaced

 

what chip? specs? street or highway?

i get 230 max on 10 gallons...23mpg on a STOCK b18c5 chipped with a jun chip actually for stage 3 cams. dynoed it 174 124 with a clogged cat. no mods

how big is your tank? arnt cxs like 8 gallons?

 

cx tanks are about 8-8.5 gallons. I'm using a skunk2 chip with bolt ons and aebs manifold. I drove the car on the highway with a full tank for about 180 miles and came back with only a gallon left compared to my 95 integra LS with the same distance and spec and it barely tipped the 1/2 tank.

 

stock tranny? sounds kinda right to me.... like i said highway i get 23mpg, but then i AM running rich at idle and low rpms

 

Get a stock b16 ECU if you can. You can run that for daily driving. I experienced the same thing you are with my chipped p72. I got 220 on a full tank when usually get 280-300

 

maybe i wasnt clear or something. you need to check the af ratio. otherwise youre just guessing.