HELP! P0131

Dominic.. · Post by **Dominic..** » Tue Mar 15, 2005 3:19 pm

Hello.

I have seriously problem with P0131 error low voltage...

Primary O2 sensor is OK, I replace for new and these same error!

When engine start, voltage going down from 0.08V to 0.03V, when is 0.03 then engine stop, and show error! Error show after 30sec work engine.

I would like know, it could be reason to rich fuel?

thank you for any advice!

Post by **Spunkster** » Tue Mar 15, 2005 5:27 pm

You will need to give more info...what ecu, what engine, what vehicle?

Dominic.. · Post by **Dominic..** » Tue Mar 15, 2005 11:39 pm

Euro Civic Type R, engine k20a turbo, 750cc injectors,

alright working fine, I installed new turbo, bigger injectors, new exhaust.

and after start engine I saw this error.

I`m sure that O2 sensor is OK!

it is possible that P0131 error is problem with to rich or to lean fuel?

Dominic.. · Post by **Dominic..** » Wed Mar 16, 2005 12:14 am

I check once again and connect wideband O2 sensor!

When engine cold, engine start without problem,

rpm are conctant 1300rpm, a/f ratio is perfectly , constant 14,7 on wideband sensor!

after 2-4 minutes engine got some temperature, then idle maked poor, moving from 800-1300rpm, and a/f ratio is moving very fast from 15:1to 23:1 , 30 second after moving idle and a/f ration showed error P0131 and engine stop

every start engine is problem, CEL on after 30sec.

Post by **Spunkster** » Wed Mar 16, 2005 10:19 am

What is your long and short term fuel trim? What ECU are you using?

Dominic.. · Post by **Dominic..** » Wed Mar 16, 2005 2:45 pm

fuel trim is 0%,

what that`s mean what ecu?

It is Kpro for Euro Civic Type R. What kind info you need?

Thank you.

Post by **Spunkster** » Wed Mar 16, 2005 3:34 pm

What is the code on the side of your ecu?

Also what callibration are you uploading and what version of K-Manager are you using?

Post by **Hondata** » Wed Mar 16, 2005 3:36 pm

When posting KPro problems please tell us:
- What vehicle, model, ECU & calibration
- What wierd modifications you have done that you're not telling us about
- Post the calibration
- Post a short datalog of the problem occuring

Are you running the Euro or US O2 sensor?

P0131 usually indicates no connection between the ECU and O2 sensor. Trace the wires as per the book. See this post

Dominic.. · Post by **Dominic..** » Thu Mar 17, 2005 12:57 am

I will try do all what you reccomend soon,

but what I know,
Honda Civic Type R, PRA ECU, customs calibration for turbo.

It couldn`t be wired problem, becouse I never touch any wiring, especialy for O2 sensor!

Important, In my previous setup all works good,
Now I`m only modification fuel system: change fuel lines for bigger, change turbo, exhaust.

So I`m looking problem in my last modification!

So this is reason why I ask about fuel , If I have to rich or to lean it could be p0131 error?

After start engine volts on O2 sensor going down from 0.30v, go to 0.02V even to 0.01 then CEL on. Low voltage that`s mean lean or rich fuel?

Even in Honda service manual in P0131 error, in some steps is reccomend check fuel system!!!!

thanks