Confounded by OBDII Readings (read story to understand why)

Here is a story of my nearly completed project of getting my new 2003 Prius back on the road.

Fabricated and installed new OBDII Cat converter, mid-pipe and brand new O2 sensors. It works good but I am trying to figure out what to do about the vacuum line that went to the now nonexistent HCAC valve. I plugged it for now (Gen2 Prius do don't have the HCAC, I believe Toyota figured out it was a bad idea)

Repaired p3030 code by servicing HV battery, replacing 2 bad cells and replacing the contact rails. Now I am getting p3006 (reads as 'pending') code (unbalanced charge). After I start the car and it warms up, I clear the code and it doesn't come back till the next morning's cold start.

Repaired p0440 EVAP malfunction code by replacing a leaking line on the vacuum check valve.

The car drives good and reliably with plenty of power, and with out any warning lights or engine light.


Here's where I need help:

I need to pass NH state inspection, which is not too stringent but they do check for engine light and for OBD codes.

The only code that shows in my OBDII DTC is the p3006 (pending) code.
However, after a good drive, I check the OBDII Emissions section and it shows;

*Catalyst - fail. It's a brand new OBDII Cat and there are absolutely no exhaust leaks.

*Oxygen Sensor (MID) Heater - fail. All O2 sensor terminals test good and O2 sensors are OEM correct and new.

*Oxygen Sensor (MID) – fail.

*2O2B1 – n/a

*All else – pass


The Live Chart readings of sensors show;

*MAF in spec,

*1O2B1 sensor volts in spec,

*2O2B1 sensor volts in spec,

*1O2B1 Trim generally in spec, does drop down in a big spike on deceleration or when engine stops. New OEM Sensor.

*2O2B1 Trim does not show on the chart. This is a brand new OEM Sensor.


I am a bit frustrated. Everything is serviced.

Mechanically I believe I have covered everything that can be covered about this emissions system.

It seems that the emissions issues on the OBDII Emissions section are not significant enough to trigger engine or warning lights.

Personally, I always make certain that my vehicles meet all requirements before I take them in for inspection.

Per all of my work and detailed research on this car, it's exhaust system, it's emissions system, and both batteries and charging system, this car should pass NH State inspection with flying colors.


Is it possible that the missing HCAC valve or it's vacuum hose I plugged are causing these readings?

Any ideas out there?

 

Yes! to the letter. Plus 40+ years tech experience , including emissions trouble shooting. I'm old and retired now and this has me confounded between the OBDII Emissions reading <vs> What I have meticulously serviced and how well the car performs.

 

Yes it is weird and I am perplexed at what to do to make this car pass in inspections.
I'm taking it into my local inspections station this Monday to have their emissions mechanic look at it.
I fear that it could turn into an expensive visit that I can't afford on my retirement income. (That is why, as a veteran mechanic, I always DIY my service and repairs before going in for inspections)

About the only thing I have left hanging, as I have covered pretty much everything else, is the issue of the missing HCAC and what to do with the vacuum hose that went to it.

Perhaps with out the flux of the vacuum tube it is sensing that I am missing manufacturer ID components and so it is failing the O2 and Catalyst and everything related in turn.

How are other people installing other aftermarket cat pipes that don't have HCAC with out having this issue?

One person who said that he had the similar issue showed me that he attached the HCAC canister aside of the exhaust pipe and ran the vacuum tube to it to "fool' the system that the HCAC is in place.

I've been trying to find any old vacuum activator canister (even from an old distributor etc) so that I could attach it as an experiment to see if it would work, but I just can't find an old one laying around anywhere to use, and I am not willing to spend the $20 for one at the parts store for an experiment that might not work.

I am hoping that somebody can give me an "ah ha" moment and show me something I have overlooked.