i know there has been a ton of threads on chipped ecu's vs systems like hondata and the such and that is NOT THE ISSURE HERE... i will be going to hondata in the future but for now im running a chipped p28 w/ VAFC. One of the major knocks against the chipped ecu's is there lack of CEL throwing when there actually is a problem. for example:

I dont have an o2 sensor hooked up right now (comin in the mail as we speak). On an unchipped pr4 ECU i have, it throws the CEL (code 41) but on the chipped p28 it doesnt. My question is this, do the chipped ecu's that dont throw codes for certain sensors even look for them at all? meaning, if i take the time to put my o2 in, will my chipped p28 even be reading it? Thanks for any help in advance guys....

most chipped ecu's bypass the basic cel's. even when you put the o2 sensor in, it will not even detect that it's now there.

Thats bullshit. so when i go to get my car dyno'ed and tuned, wont this be a prob?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eRaceParts.com &raquo;</TD></TR><TR><TD CLASS="quote">Get a cheap air/fuel ratio meter. If the o2 sensor is working with the chipped ecu, the ratio will swing from lean to rich and back and forth constantly at light throttle and cruising conditions. Then under full throttle the ratio will stay steady near rich and stochiometric. more towards rich if it's running properly.

I would say the chipped ecu still uses the O2 sensor, but just blocks the error codes from registering.
Chipped ecus like the real Mugen or other true N1 programs do run open loop (no O2 input). Good luck!</TD></TR></TABLE>

thanks for the input!