Hi Guys,
I'm about to lay down a lot of info pertaining to an issue with my Civic that's persisted for the last 4 years. I can get around it by running my OBD1 tuned ECU, which I do daily. But when California smog time comes, I'm screwed and end up paying a little extra to pass smog...

I've searched on this topic, and the internets found a wide variety of issues, but not mine. I want to see if anyone has had this exact problem, and what component(s) were the cause.

Here's the setup
1999 Civic EX
B18C-R (JDM) OBD2A converted to OBD2B, and using a OBD2B P73 ECU
Stock EVAP system - everything is connected (Civic EVAP connected to the ITR motor and ECU just like it would in an ITR minus the ITR part numbers)
I just replaced both primary and secondary O2 sensors with OBD2B ITR O2 sensors. I figured and ITR ECU should be fed data from ITR sensors.

I run the car on a tuned OBD1 computer, there are no CEL issues on the OBD1 computer, and the car runs excellent, but it's California smog time, and I need it to run just as well off the OBD2B P73 ECU...

Here's a pretty picture of how I routed the EVAP system:


Before I go any further has anyone done this swap and kept it Cali legal with my setup? The incomplete monitor is actually not a problem. I can pass smog with an incomplete monitor. But I cannot pass it with the CEL for the rich condition. It was running so rich I had to open the windows at stop lights, and after I got the DTC I immediately swapped out the oil and went back to OBD1.

Another important symptom happens when I plug in the OBD2 ECU:
While cruising I hear the lines (my guess is number 1 in the diagram) running to the EVAP purge solenoid slapping up against the brake lines along the fire wall. The slapping noise is the result of the EVAP purge solenoid opening and closing rapidly is my guess, and the resulting pressure release causes the lines to slap around even though I have them zip tied fairly well. This could indicate the fuel tank pressure sensor is bad... but I'll get to that in a minute.

Tonight I pulled out all the EVAP components that I can get to without dropping the tank. I tested the EVAP canister vent shut valve and EVAP purge solenoid valve and they both click open when 12V is applied. Tomorrow I'll hook up a vacuum and follow the 7 pages of diagnostics provided by the manual. And F.M.L. I will have to drop the tank and test the other half of the system if I cannot find an issue with the under the hood components.

Thanks for your help guys.

 

Dick and two *****... that answers that. I'm going in.

 

 

Alright substituting a primary O2 from a 2001 ITR was a mistake. Swapping in the Civic Primary O2 fixed the rich condition.

Next issue is I have a pending P1457 stored in the ECU. After performing diagnostics it looks like the EVAP purge solenoid valve is not opening. I checked the routing and it looks like I plugged in the evap purge solenoid up-side-down. Which means the intake manifold side is plugged into the canister. I'll fix the routing and see if that fixes the valve.

 

Today I resolved this issue. The EVAP was routed incorrectly. The evap purge control solenoid should have been routed directly into the intake manifold, which I did and the EVAP monitor went into to OK status after a few minutes of driving.

I am pleased to say that I have a California Legal JDM B18C-R swapped Civic. Passed with flying colors on emissions.

 

Here's the corrected routing