Smog question

[sandawgk5]

I just smogged my k5 cause I have to register in Cali now. It passed but barely.

I live in an enhanced county so I have to do the dyno testing. here are the results.

timing 0 tdc
15 mph / rpm-1460, hc-118, co-.28%, no-808 max / 120-.74%-1045

25 mph / rpm-1408, hc-74, co-.31%, no-595 max / 92-0.93%-1040

The hc and no at 15 mph are what concern me they are really close to the limit. I need and oil change could this be causing the high readings or possibly my cat is going bad. I drove the truck for about 15 min before I went to the test station and only sat for maybe 2 min waiting to go in. I have 2 years before I have to do it again so it is not a big concern right now. Oh yeah the engine has 179, 815 miles on it could that be why hc and no are high. Thanks.

 

[sandawgk5]

Anybody? No body?

 

[K5MONSTERCHEV]

Wait, it passes? Whats the problem? I think it will fail because the timing is out of spec, I think its supposed to be at 6* +/- 3*. What does it say on the underhood label? You want the cat good and hot before you smog it.

 

[sandawgk5]

87 is FI underhood label says 0 tdc for timing checked with ecm disconnected. I do not know if they actually did that part. I was rather surprised because I timed it the redneck way by listening. I do not own a timing light. Shouldn't the ecm control the timing anyway? Yes it did pass I got my new plates today I was just concerned about the high HC and was wondering what some of the culprits could be.

 

[K5MONSTERCHEV]

First thing I would say is to see what the timing is at. They will check it and if its out of spec, they'll fail you. ECM does control the timing retard, but you have to set base timing.