I was throwing code P0140, SHO2S heater circuit malfunction. Installed a KTeller o2 sim, & universal o2. After this car threw another code. A P0172 or code 45. Fuel system running rich. What would cause this? Are the two related? I thought a secondary o2 would not effect the a/f ratio. Also, I replaced spark plugs, wires, distributor, fuel pump, fuel filter & evap purge control solenoid valve. Fuel pressure is within spec. What could be causing my problem? Please help, need to pass smog ASAP!

 

As the code states, you're running rich. The O2 sensor is reporting to the ECU a high voltage (instead of swinging back and forth). The ECU tried to correct this and when it uses up all of its adjustment, you got the code.

So you're either running rich or the O2 is duffed.

 

Still running rich & throwing code P0172. I replaced the injectors & installed a VAFC2 since last post. Took it to the dyno and had it tuned (on old injectors). Everything with the fuel system has been replaced. What the hell is making it run so rich it throws a code. Would a plugged cat cause this? Any ideas?

 

Forgot to mention I also replaced the PCV valve.

 

Have you tested your primary o2 sensor? It could be biased rich.

 

The sensor is brand new it should be good. How would I go about testing it to make sure?

 

what mods do you have? is the fuel system all stock? you did put the 02 sim on the secondary sensor right?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2000psi &raquo;</TD></TR><TR><TD CLASS="quote">what mods do you have? is the fuel system all stock? you did put the 02 sim on the secondary sensor right?</TD></TR></TABLE>

The fuel system is all stock (brand new fuel pump, filter, injectors, PCV valve). Installed test pipe, new stock thermostat (had worthless Mugen). yes, o2 sim is installed on the correct sensor.

All out of ideas!

 

Which 02 sensor did you replace with the "universal 02"? That sensor might not have the correct range the Honda ECM is looking for.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2000psi &raquo;</TD></TR><TR><TD CLASS="quote">Which 02 sensor did you replace with the "universal 02"? That sensor might not have the correct range the Honda ECM is looking for.</TD></TR></TABLE>

The primary! Is there a way to test it?

 

Get an OEM 02 sensor...don't skimp on something so important like the primary 02, the difference in gas mileage alone will pay for itself in a few months vs an offbrand 02.

 

you could always test it by installing a wideband and seeing if you really are running rich or if it's just the sensor....but thats neither here nor there. good luck

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by brnyrdcmndo &raquo;</TD></TR><TR><TD CLASS="quote">Please help, need to pass smog ASAP!</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by brnyrdcmndo &raquo;</TD></TR><TR><TD CLASS="quote">Installed test pipe....</TD></TR></TABLE>

How about you go back to stock for the time being to pass smog??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by EE_Chris &raquo;</TD></TR><TR><TD CLASS="quote">

How about you go back to stock for the time being to pass smog??</TD></TR></TABLE>

The testpipe won't make a difference as there is no 2nd o2 sensor because I'm running an o2 sim. The car is OBD2 so they don't sniff it, just check the computer.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2000psi &raquo;</TD></TR><TR><TD CLASS="quote">you could always test it by installing a wideband and seeing if you really are running rich or if it's just the sensor....but thats neither here nor there. good luck</TD></TR></TABLE>

I have a wideband installed, and yes it shows I am running rich.

 

how does it drive? all I can think of is that you have a leaking injector(s) since thats the only thing not replaced.

 

Nope! All injectors were replaced.

 

Have you checked your fuel presure? What year and model is the car?

 

You can test the 02 sensor by measuring the millivolts it produces with a voltmeter on the high and low reference wires from the sensor. 1000mv = rich, 100mv=lean. 450mv is stoitchiometric which is the perfect air fuel ratio, 14.7-1.