djkrisg

hey guys,

I'm turning to what i believe is the most informative Honda website for help.

i have a 2000 civic si w/ stock ECU. it has the JDM 10.4 comp block. i also have a AEM 2.75" intake, Skunk 2 type R intake manifold, greddy 4-2-1 header, stock cat and 2.5" n1 style exhaust.

i cannot get rid of cel p0131 bank 1 sensor 1 low voltage. the light will go on after idling for 5-10 mins or driving very light footed for a while. but not if i drive it somewhat normal or hard. only when i hit traffic or driving not too get pulled over

i have not checked my fuel pressure, but my spark plug color has indicated somewhat stoichiometric or normal mixture.

my question is: is this most likely a rich/lean condition? or an o2 sensor on its way out? it might be the original w/ 163k on it. it is def a plug & play 02 sensor , i havent figured out if its the original or oem. but it is clipped into the wire harness, with no splices. i hit that uncorroded connection w/ dielectric grease just to be sure it wasn't faulty connection.

i was getting the code p0172 system running rich & p0170 fuel trim malfunction for a little while 6 months ago. than i messed with my o2 sensor, cleaned my dirty air filter.

and it has been been popping off w/ p0131 ever since. it will go for 300+ miles w/ no code and than it will go on in 20 miles as soon as i idle or lightfoot it for 5-10 mins too long.

anyone have some ideas on what too check in order to get to the bottom of this?

Former User

My suggestion: Measure the fuel pressure. If it's fine, then replace the O2 sensor.

djkrisg

cool, i will do that as soon as i get my hands on the proper gauge.

i saw something on here about how to do that w/ a fuel pressure gauge @ the filter, and playing w/ regulator vacuum to check the regulator. my reg is oem and old.

i guess my only real option for the 02 sensor is OEM denso, correct?

thanks for your help