After fixing my 2.5 L, I have trouble passing CA emissions. I have gotten it tested twice and both times problems in same area with similar numbers. They are as follows:

I have failing HC and NOx. Hax high CO at 15 mph but passing. I don't have test 1 in front of me but is similar to test 2. See the attached thumbnail for test data.


Before test 1:

Timing belt
Plug wireset
Ignition coil
Ignitor (Chevy mod)
Pre-Cat O2 sensors both
Fuel filter
Air filter is clean
Cleaned EGR ports and verified flow
FlowMonster catalytic converter
Pre-Cat gutted by previous owner
Replaced some vacuum hoses and verfiied correct placement
Ran Lucas fuel system cleaner
87 octane fuel
Cleaned throttle body and IAC.
Reset the computer and took it for testing without much driving. Left the engine off for 5-10 minutes while waiting for the test.


Before Test 2:

Bank 1 pre-cat O2 sensor replaced. Kept getting only P0130 code
Another brand fuel system cleaner treatment
91 Octane fuel
400 mi+ driving at various speed conditions
Keep getting TCS OFF light. Goes away when I start the car but comes back after a few miles.
Oil change
Verified EGR operation while driving. Get couple psi of vacuum at a steady speed which jumps up to around 5 psi under acceleration.
Kept the car hot even when waiting for the test.


What do you guys say about gutted pre-cats and FlowMonster catalytic converter arrangement?

 

Hellllo, anyone out there.

 

1) I say stay off the 91-93 octane unless the car requires it. That's an HC killer right there. (Incomplete burn.)
2) Fuel tank installed cleaners (in a can) don't work. Get a pressurized system the runs directly through the fuel rail/injectors.
3) You may also have a vacuum leak based on your testing. Vacuum should be steady at a steady speed, not fluctuate.
4) Your AM cat may not be working as well with the older engine as you would like.
5) Could you be getting a mis-read from the O2 sensors in the gutted pre-cats?

BTW: These are mostly guesses based on what you've said about the car and it's condition.

 

I'm sooooooo glad I don't live in CA anymore.

 

Living in CA is not bad even with stringent smog requirements. I've had a number of high mileage 200+ non-CA cars that passed CA smog with flying colors. The thing to do is to keep the cars maintained.

My vacuum is stable and I've tried searching for vacuum leaks with all sorts of stuff like propane, starter fluid, brake fluid, water and no luck. The engine could have a lot of carbon in it because the previous owner had the spark wires all crossed which turned the previous cat into dust. I installed a new one because of that. How much cleaning do I need to do?

One other thing. After the injectors are fired they drip for a little bit at a pretty good pace before they completely cutout. I tested this out of the car. How normal is this?

 

This is what I am thinking after a little bit of sleep.

The injector drip as described above is not normal even if it is for a few seconds after they turn off (SOMEONE PLEASE CONFIRM). The drips are causing rich mixture, hence high HC and CO readings at 15 mph. The computer is trying to cutback on fuel because the O2 sensors detect this and I can see the car computer doing this on my laptop. Because of the cutback (~7%) I actually have a lean mixture in the cylinder causing high NOx. At 25 mph this effect is minimized because of faster engine speed. The cutback I see is around 2%.

Would be really great if someone can confirm this. I know there are Millenia 2.5L geniuses on this forum.

 

This is what it looks like (see thumbnail). All six are the same. Looks awful to me, what do you guys think? They do not drip after close anymore like I said in the previous post. The cleaners must have cleared that up.