Bad gas mileage with swap???

[VTECFREAK]

I did a H22 swap into a 4th gen accord a couple months ago, and ever since then my gas mileage has gone down considerably. I've read somewhere that it's a sign of a bad o2 sensor, but just curious what else could be causing this problem?? Any Ideas??:

[jdmhonda98]

i would change the fuel filter and the plugs first.

[ricertypeR]

what do u mean considerably?

the h22 will use more fuel to run
and chances are ur running it hard!

[ExViTermini]

the h22 when run hard uses loooootttttssss of gas...they run rich as hell...in my civic I get shit for gas mileage if I run it...but I get better than stock if I'm nice to it..cuz the motor isn't working hard at all

[jdmhonda98]

i think they come with 360cc injectors stock.

[scottigee]

I know you did an H22, but if it helps I went B18C (GSR) in my civic hatch and I have gotten 35mpg without trying all that hard. Typically I'm around 30mpg with a lot of city driving....and hard...

all these recommendations sound good

[EFtypeR]

Check your o2's, and if more than one, make sure they are wired in order, in the right place. I got 10 less MPG until I swapped the new o2's wires and re-welded to the stock locations, and I have an OBD-0 ecu! Go figure, keep the emision sensors stock as hell....