Smog fail. need to run leaner
Thread Starter
Teching In
Joined: May 2005
Posts: 6
Likes: 0
Thread Starter
Teching In
Joined: May 2005
Posts: 6
Likes: 0
frost is correct my HC is high. what can i do to bring it down?
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Staging Lane
Joined: Jun 2010
Posts: 69
Likes: 0
From: Kingfisher Oklahoma
hmmm I really hope they dont get emissions in oklahoma or were all screwed out here lol . you can use hp tuners to lean out your car but you need to make sure everything else is in order .. are your headers leaking ? o2s fluctuating or are they lazy? lots of things can cause a rich condition
Last edited by whtrashferrari; Sep 14, 2010 at 04:23 PM.
i think you need a new set of cats. Get a new, high quality set and you should be ok. The o2's are probably fine since you aren't throwing any codes.
I went thru the same **** with ca smog... put the factory manifolds and cats back on and I passed.
I went thru the same **** with ca smog... put the factory manifolds and cats back on and I passed.
If you have your own software, run a data log of it idling. In the data log, include fuel trims, both short and long term, and both upstream and downstream O2s. I would almost guarantee it's a catalyst efficiency issue. Both your Hcs and CO2 are borderline. If it is a catalyst efficiency problem, not much you can do with high flow cats. Shoot me a PM for more details.
Looking back at your mods, I believe the LG longtubes put the cats way in the back, as opposed to right behind the headers. They never get hot enough (the cats) to kick on.
Looking back at your mods, I believe the LG longtubes put the cats way in the back, as opposed to right behind the headers. They never get hot enough (the cats) to kick on.
I think you want brand new O2 sensors and you want them
as hot as possible. The headers hurt that, making the sensors
switch more slowly and when they do your mixture (while on
average, perhaps right) spends a lot more time off in the
weeds, lean, rich, lean rather than tight, tight, tight. Out in
the weeds is where you make HC. If you want to look into
this, turn off the filtering on your wideband and log real time
idle AFR. If it's bouncing crazy, there's your HC.
I'd consider wrapping the collector for maybe 6" before and
after the sensor with a heat barrier. At least until you get
your sticker.
as hot as possible. The headers hurt that, making the sensors
switch more slowly and when they do your mixture (while on
average, perhaps right) spends a lot more time off in the
weeds, lean, rich, lean rather than tight, tight, tight. Out in
the weeds is where you make HC. If you want to look into
this, turn off the filtering on your wideband and log real time
idle AFR. If it's bouncing crazy, there's your HC.
I'd consider wrapping the collector for maybe 6" before and
after the sensor with a heat barrier. At least until you get
your sticker.
TECH Senior Member
Joined: Apr 2002
Posts: 6,080
Likes: 17
From: So.Cal.
+1 on taking logs to see how O2's are switching... you probably do need new 02 sensors.
Are coldair/headers/exhaust the only mods you have...? Your emissions should be well below the average. I can't read the .hpt file, so summarize for us what has been edited in the tune.
How did you get past visual...?
Are coldair/headers/exhaust the only mods you have...? Your emissions should be well below the average. I can't read the .hpt file, so summarize for us what has been edited in the tune.
How did you get past visual...?
