My car is throwing a P0141 (secondary o2 sensor isn't in the car.) and it's also throwing a code P0450 .. I looked on the ecu code page, and there isn't a P0450 on it?

Any help would be appreciated.. trying to get rid of this damn CEL so i can send my car through inspection.

 

bump.

 

anyone?

 

Well its an emissions code. The only thing I could find about it is the charcoal canister is not doing what it needs to do (PO443). Considering all PO codes are the same for all vehicles and I only found one instance its just a stab in the dark.

 

P0450 Evaporative Emission Control System Pressure Sensor Malfunction

 

anyone know where that sensor is?

 

Tighten your gas cap.

 

 

I know why it's throwing P0141, it's cause there isn't a secondary o2 hooked up to the car, i need to weld in a bung and put one in.. i'm trying to figure out the 2nd code it's throwing, P0450.

Anyone had this code before, how did you fix it? replace the sensor?

EDIT: That's a very helpful diagram though, thanks

 

Ok, so my car is throwing a P0450.

P0450 Evaporative Emission Control System Pressure Sensor Malfunction

Just to clarify, I have a 99 Honda Civic (OBD2B.) And i have a 97 B18b (OBD2A) using that year ECU in my car, i bought a OBD2B>OBD2A Conversion harness.

I've been looking at the pinouts for both year OBD's. I've found three "EVAP" related wires..

VSV - EVAP Control Canister Vent Shut Valve.
PCS - EVAP Purge Control Solenoid Valve.
2WBS - EVAP Bypass Solenoid Valve.

Looking at my wiring harness and where it attaches to my Conversion harness at the ECU. I can see that the "PCS - Evap purge control solenoid valve" Is hooked up and goes to the correct pinout on the ECU.. now NEITHER wire is connected to the other two, the EVAP canister vent shut valve, or the EVAP Bypass solenoid valve. Could these two wires that aren't hooked up to the ECU be causing my code it's throwing, P0450 Evaporative Emission Control System Pressure Sensor Malfunction?

Any help would be appreciated!

 

bump..

 

the evap system monitors pressure through the fuel tank pressure sender. When the evap monitor is running, the purge solenoid opens while keeping the vent solenoid shut. This applies a vacuum to the canister, lines, and fuel tank, and the ecu monitors the ammount of vacuum it can apply by using the fuel tank pressure sender. It also monitors how long it can hold that vacuum for, which is it's way of leak detection. Hence why you get a check engine light when you have a loose gas cap.

However i'm willing to bet that there's actually something wrong with that sensor because if your cap were loose ( or you had a leak) it would set a code telling you it has a large or small leak in the evap system. Chances are if it says your perssure sender isn't operating correctly, you may have a wiring problem, or the sensor may be bad. Considering the car is OBD2, the car has the ability to detect erroneous readings from any sensor, so there is the possiblity that something could have messed it up, and everything is okay. Clear the code and see if it come back, if it does, then start with the fuel tank pressure sensor wiring. I believe it's listed as FTP on the ecu chart. Good luck

 

Check gas cap flange for rust also