Smog Test? Dyno or Idle

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Feb 26, 2003
Next to the Falls in OH
I have searched back at most of the smog threads and need some advice.
If you had the option to take the test on the dyno wheels spinning some asshat driving the truck with no clue or would you opt for the test being performed while the truck is in neutral not spinning.
My CO was 3.60% limit was 2.49% so it was close. (Truck was on dyno)
After reading all of the smogg post I will put in the new air pump and bypass the switch and go straight into AI rail and of course cross my fingers.

Would you expect lower CO#s if the truck was not under load?
Pull of the inlet to the air pump on the air cleaner and make sure your new pump is pulling a decent amount of air at idle. If that is the case, then try testing it at idle. I don't really know which would give you lower CO numbers.
I don't think you get a choice. It's a regional thing in California. Good luck.
Your are right about not being given a choice but.

If you tell them that "It is stuck in 4wheel drive" they can not put it on the dyno. If you have a full time 4 wheel drive they just rev. the engine. So I wondered if you let them test it without a load "dyno" would your CO number be lower.?

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