My understanding of CIS-Lamda is that as long as you are close, the base mixture setting isn't all that important because the Lamda system will try and bring it back to stoichiometric with the frequency valve, except when the engine is cold, or at full throttle where it goes open loop. Is this incorrect?
The odd thing is I took it back today, and it was actually slightly worse. He put it on in diagnostic mode, so it just displayed the numbers on the screen, and he said it failed even at 15 MPH now.
He insists he can't run the test in 3rd gear.
I took it back to the place I got the pre test, he did the same thing, but printed out the results for me..
There I passed at 15 mph, but failed at 25.
At 15: 13.9%CO2, 0.1%O2, HC 13, CO .81% NO 257 Only one close to limit (.99)is CO.
At 25: 13.9%CO2, 0.1%O2, HC 15, CO .84% NO 428 Only one over limit (.79) is CO, by a whopping .05%