just passed smog....barely.

[Jonny-K5]

just the the blazer smogged today. even with a brand new cat, new plugs and new oil change i barely squeeked by. max emissions were 112 PPM @ 15mph, and the truck did 111. the tech said its basically unburned fuel(running rich). she did better for the 25mph reading. what could be caussing this? the truck has always kinda smelled rich at idle, at least for the 4 years i've owned it.

what are some things that i could check?

oh yeah, the truck came with a performance chip. forget what brand but it requires 91 octane.
could the chip be the culprit?

 

[muddybuddy]

maybe the chip wasnt programed right in the first place????
congrats on passing

 

[K5MONSTERCHEV]

Just curious, was the truck fully warmed up? The cat has to get to 1200*F before it works.

 

[Jonny-K5]

i was driving around for an hour before i pulled into the smog station. pretty sure it was warmed up. i do have a 180* stat in for the chip instead of the stock 195*. maybe that had something to do with it.

 

[skelly1]

What year and what was the CO readings?

 

[REDCRO_REDNECK]

i was driving around for an hour before i pulled into the smog station. pretty sure it was warmed up. i do have a 180* stat in for the chip instead of the stock 195*. maybe that had something to do with it.

If you are using the stock chip your t-stat might be your problem. stock computers run better, and get better economy @195. All of mine have anyway.

 

[dyeager535]

If it's an off the shelf chip (hypertech, etc) get rid of it, piece of junk anyways. Increased octane because the timing is bumped up, that's essentially all they do.

Lower octane, higher thermostat rating, and stock chip will more than likely bring it back to where it should be.

Can't reiterate enough how crappy those aftermarket chips are.