Emissions on 91 Octane and 2 cans Octane Boost - high CO, low HC

[Yenkoman]

Well, I tried to get my new Reasonably stock engine to pass Colorado Emissions today. I was running 91 octane unleaded with 2 cans of octane boost. I was sorting out a knock retard issue at WOT. They failed me for having a Flowmaster high flow Catalytic converter (This is 49 state compliant and is the correct 3-Way so i think i can get it approved) and High CO. The CO was at 35 with a pass limit of 25. It was 40 degrees outside and engine temp at 160. They simulate a driving test accelerating up and down is speeds on a dyno. They printed Fail report that shows the CO at different vehicle speeds. Under Acceleration the CO drops and but when the let off or level off there is a large spike. So far the only adjustment to made to the chip is to lower the idle fuel on the rotary two settings and to enable the AEM Wideband on dip switch 4 Do you have any ideas?

 

[Dan B]

What kind of octane boost?

 

[Yenkoman]

LUCAS LUC10026 Octane Boost. 15 oz​

 

[Yenkoman]

They will not accept my Catalytic Converter. They are making me install a California rated Cat. That should be done today. Hopefully the CAL Cat will convert more emissions. I will burn the tank with the Octane Boost next week and then retest and see how it goes.

 

[Yenkoman]

It passed yesterday. It took:
New California rated Catalytic Converter. (Felt like a 50HP reduction over High Flow Cat.)
192 Degree Thermostat.
Original O2 not Wideband O2
Fuel Pressure down to 38 LBS.

 

[EricM]

Glad you got it passed!

 

[Yenkoman]

Well, it's been 2 years and my typhoon has failed again. On the first test, I had restored fuel pressure to 43lbs and added wideband control. The test failed on high CO. (37 when limit is 25) NOx was low (.18 with 4.0 limit). There were 8 large CO spikes. Many were at cruising speeds between 40 & 55 mph.Three happened with steady throttle at about 40 mph. I then dropped the fuel pressure to 36 and retested. CO now low (.25 with 25 limit) and NOx (4.04 with 4.0 limit) I barely failed! My next thought was to go back to 38lbs. I passed with this combo 2 years ago but CO was close then (20. With 25 limit). The chip had been reset to default settings during all tests. Does anyone have any ideas to dial back the CO spikes with FP at 43psi? Typhoon felt reasonably fine with low fp but did detonate at wot.

 

[Yenkoman]

Test 1 (high CO low NOx)

 

[Yenkoman]

Test 2 (Low CO, high NOx)

 

[EricM]

That treadmill test is difficult. I'm surprised you passed a couple years ago.
The bursts of CO might be when they press on the pedal and you get an enrichment pulse of fuel.
Lower fuel pressure may help with that. I would probably lower fuel pressure to say 35psi, then drive around a bit to let the computer relearn, (using the stock O2), then try again.
Other than that, you may need to put the stock injectors and chip back in to get it to pass.

 

[EricM]

I don't know if an E85 tune will help. Seems like it helps some and not others. It might be worth a try.

 

[Yenkoman]

Can the enrichment pulse be reduced somehow in the chip tune? With the fuel pressure at 36, the CO spikes disappeared but the NOx came up. Possibly to lean or high cylinders temps maybe. I had to wait 2 hours in the line for the test. When I make FP changes, do I need to unhook the battery or will the chip continue to learn?

 

[Yenkoman]

Also, I would need to buy stock injectors so that would not be my preference.

 

[EricM]

The NOx will be tough without EGR. That cannot be enabled in the chip (for 60's).
Trying to custom tune your existing 60lb program for emissions would be difficult.
As long as you drive around warmed up, maybe 10-15 minutes, you should be ok without disconnecting the battery.

 

[EricM]

There may be some additives that reduce NOx, but I don't have experience with it.

 

[Yenkoman]

Ok, thanks. I also heard that there are some gas additives that reduce NOx. I will explore that as an option.

 

[Yenkoman]

Would adjusting the high boost fuel or mid boost fuel effect the CO spikes I am seeing? Also what would be the cost to add the secondary e85 program to my chip?

 

[EricM]

I don't think so. They would have to be hitting at least around 7psi boost to have the mid boost adjustment take effect.

 

[Yenkoman]

What would you charge to add the e85 secondary tune?

 

[EricM]

It's $65 to add that (plus shipping). You would need to send your chip to me for programming.