lean code???
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Joined: Sep 2008
Posts: 158
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From: winter haven florida
lean code??? hey guys have a question i have a stock ls1 with basic blt ons and an exhaust. basics being a lid smooth bellow free mods. why would my car be throwing the lean code. could it be a bad o2 sensor
could be that...
could also be that you have a hole in the intake someplace, and its sucking in unmetered air.
check your ENTIRE pcv system. they deteriorate easily, forming holes and are notorious for being difficult to see.
start at the top of the passenger side of the TB, the tube running to the front of the passenger valve cover.
next the tube starting on the lower passenger side of the intake manifold snout, into the pcv valve, then running along the passenger valve cover, one hose Ts off into the rear of the passenger cover, then behind the intake and into the rear of the driver's valve cover.
could also be that you have a hole in the intake someplace, and its sucking in unmetered air.
check your ENTIRE pcv system. they deteriorate easily, forming holes and are notorious for being difficult to see.
start at the top of the passenger side of the TB, the tube running to the front of the passenger valve cover.
next the tube starting on the lower passenger side of the intake manifold snout, into the pcv valve, then running along the passenger valve cover, one hose Ts off into the rear of the passenger cover, then behind the intake and into the rear of the driver's valve cover.
What "80mm MAF" would that be?
That, vacuum leaks or lazy O2 sensor could all
be possibilities. If you have only one bank bad
then swap the sensors side-side and follow the
bouncing ball. If both banks have lean codes
then it's something "global".
That, vacuum leaks or lazy O2 sensor could all
be possibilities. If you have only one bank bad
then swap the sensors side-side and follow the
bouncing ball. If both banks have lean codes
then it's something "global".
meaning its not something isolated to one side...like one bad o2 sensor.
a leak around the TB, MAF or in the PCV system would affect both banks equally...ie..."global"
a leak on one intake runner would only affect that bank.
a leak around the TB, MAF or in the PCV system would affect both banks equally...ie..."global"
a leak on one intake runner would only affect that bank.
a leak anywhere after the MAF could cause the codes.
how long has the ported TB been on the car?
i would check the obvious first...the PCV and all the gasket and clamped connections ahead of the manifold.
if you have scanning software you can watch the long term fuel trims (LTFT). i had a hole in my PCV system and my trims were ~24-25%...the code trips when the fuel trim exceeds 25%.
that percentage means the computer is seeing more air than it should, so the engine is running lean...and it's compensating by adding 25% more fuel.
how long has the ported TB been on the car?
i would check the obvious first...the PCV and all the gasket and clamped connections ahead of the manifold.
if you have scanning software you can watch the long term fuel trims (LTFT). i had a hole in my PCV system and my trims were ~24-25%...the code trips when the fuel trim exceeds 25%.
that percentage means the computer is seeing more air than it should, so the engine is running lean...and it's compensating by adding 25% more fuel.
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yea i had a hole in the hose that ran from the pcv to the intake and my car started throwing lean codes i just used a small hose and just replaced the one with the hole in it it was better than spending over 180 to buy the whole assembly
might try clearing the computer of all the "learned fuel trims"
that way you can start from zero and see what happens.
23-24 is still pretty lean. sounds to me like there is still a hole. or else the computer is jsut slowly readjusting.
keep us posted
that way you can start from zero and see what happens.
23-24 is still pretty lean. sounds to me like there is still a hole. or else the computer is jsut slowly readjusting.
keep us posted
i realize that...it still seems high for idle.
could be other things contributing.
you could try plugging the vacume port on the manifold and seeing what happens to the fuel trims.
if they drop, you know you still have a leak.
don't do it for long...but for 15min of idling it wouldn't hurt
could be other things contributing.
you could try plugging the vacume port on the manifold and seeing what happens to the fuel trims.
if they drop, you know you still have a leak.
don't do it for long...but for 15min of idling it wouldn't hurt
