Running Lean

Huff94 · January 18th, 2012, 06:08 PM

Everything was running good until a few days after changing my airfilter to a K&N filter. Now im getting a code that im running lean. Any ideas?

Huff94 · January 18th, 2012, 06:32 PM

I put a new fuel filter,crank/cam sensor,maf,and plugs. It is acting very sluggish. also have Accel Coil pack

xtreme 2 · January 19th, 2012, 10:00 AM

can't see a filter change causing those problems.

describe sluggish? there is v6 engine sluggish, then there is problematic sluggish, LOL

WickedSnake00 · January 19th, 2012, 11:08 AM

Just some random thoughts for possibilities-

Did you modify anything that may be causing a vacuum leak when you installed your filter and MAF? Maybe the MAF isn't installed properly?

Is is the correct MAF?
A MAF with the wrong transfer function can cause you to run lean.

xtreme 2 · January 19th, 2012, 11:19 AM

that's true. If it's calibrated for a different injector setup it will throw you off.

Same if you forgot to plug the IAT back in or anything of the sort.

Any CELs?

Huff94 · January 19th, 2012, 07:19 PM

no i didnt mess with the MAF or anything when i swaped to the K&N filter. I just opened the box took the old filter out put the new one in. I just took the MAF out and cleaned it with the MAF cleaner. still running lean.

Huff94 · January 19th, 2012, 07:28 PM

sluggish as in problematic. once its going there is power but trying to get it going is like im trying to take off in 2nd. a few of my sparkplugs are black and sooty

WickedSnake00 · January 19th, 2012, 07:36 PM

Well you also said you changed MAF's. Is it the correct P/N? An incorrect transfer function can cause you to run lean, as well as unmetered air, aka a vacuum leak. Take a look at those.

Huff94 · January 19th, 2012, 07:44 PM

i changed the maf a few months back so i was just guessing that it wouldnt be a bad maf now..when i start the car up cold it boggs down and some smoke comes out the pipes for a min then its all good.

Nate3.8 · January 20th, 2012, 10:09 AM

mine was doing the same thing was passenger side upper o2 sensor. now runs good

Huff94 · January 20th, 2012, 12:12 PM

yeah thats what im thinking im going to have to change.. im going to take it to autozone to have them read it again to see if its still running lean. see if cleaning the MAF fixed it or not

xtreme 2 · January 20th, 2012, 02:08 PM

what is the exact code you are getting?

which side are the spark plugs messed up on?

Huff94 · January 20th, 2012, 07:39 PM

i changed back to the stock airfilter and drove 70miles and no code came up. now i just changed back to the K&N . im going to see if it starts running lean again

Puffy93 · January 20th, 2012, 07:59 PM

try disconnecting your battery for a couple of minutes to reset the computer, the computer is used to the air flow from the stock filter and the increased flow from the K&N is confusing it and making it think its going lean.

Huff94 · January 20th, 2012, 08:07 PM

i did every time i swapped it out..thats why i dont under stand why it says its lean every time i put the K&N in

Huff94 · January 20th, 2012, 08:27 PM

i took out my spark plugs and a few of them are indicating that that cylinder is running lean. im starting to think that all of my problems are coming from some bad injectors. what do you think

Puffy93 · January 20th, 2012, 08:38 PM

Try starting the engine and spray the area you worked on down with carb cleaner or starter fluid around the area you worked on, if the idle raises then there is a vacuum leak there causing you to go lean. i would do this before you start replacing injectors.

Huff94 · January 20th, 2012, 09:28 PM

will try it

WickedSnake00 · January 20th, 2012, 09:41 PM

Yup. Check the major ones before you go replacing injectors.

Check for vacuum leaks, check that your MAF is correct, and test your oxygen sensors.

Huff94 · January 20th, 2012, 10:09 PM

whats the best way to test the o2's

January 18th, 2012, 06:08 PM	#1
Huff94 Newbie 94 Mustang 3.8 Join Date: Jan 2012 Location: Suffolk VA Posts: 38 iTrader: 0 reviews	Running Lean Everything was running good until a few days after changing my airfilter to a K&N filter. Now im getting a code that im running lean. Any ideas?

January 19th, 2012, 10:00 AM	#3
xtreme 2 Hardcore Enthusiast 2001 v6 premium Join Date: Nov 2008 Location: Tulsa, OK Posts: 1,340 Blog Entries: 1 iTrader: 0 reviews	can't see a filter change causing those problems. describe sluggish? there is v6 engine sluggish, then there is problematic sluggish, LOL __________________ Screw it, coming to play with the big boys... 5.4L Vortech COMING SOON!

January 19th, 2012, 11:08 AM	#4
WickedSnake00 MM's king of Neon's 404 - car not found 17.81@87 Join Date: Aug 2010 Location: Diesel Engine Capital of the World, Columbus, IN Posts: 7,376 iTrader: 0 reviews	Just some random thoughts for possibilities- Did you modify anything that may be causing a vacuum leak when you installed your filter and MAF? Maybe the MAF isn't installed properly? Is is the correct MAF? A MAF with the wrong transfer function can cause you to run lean. __________________ Official Secondhand Snake Build Thread Here Looks Like a Cobra, Sounds Like a Cobra, Tastes Like a Cobra, Not a Cobra. For Sale: P71 Interceptor motor

January 19th, 2012, 11:19 AM	#5
xtreme 2 Hardcore Enthusiast 2001 v6 premium Join Date: Nov 2008 Location: Tulsa, OK Posts: 1,340 Blog Entries: 1 iTrader: 0 reviews	that's true. If it's calibrated for a different injector setup it will throw you off. Same if you forgot to plug the IAT back in or anything of the sort. Any CELs? __________________ Screw it, coming to play with the big boys... 5.4L Vortech COMING SOON!

January 19th, 2012, 07:36 PM	#8
WickedSnake00 MM's king of Neon's 404 - car not found 17.81@87 Join Date: Aug 2010 Location: Diesel Engine Capital of the World, Columbus, IN Posts: 7,376 iTrader: 0 reviews	Well you also said you changed MAF's. Is it the correct P/N? An incorrect transfer function can cause you to run lean, as well as unmetered air, aka a vacuum leak. Take a look at those. __________________ Official Secondhand Snake Build Thread Here Looks Like a Cobra, Sounds Like a Cobra, Tastes Like a Cobra, Not a Cobra. For Sale: P71 Interceptor motor

January 18th, 2012, 06:32 PM	#2
Huff94 Newbie 94 Mustang 3.8 Join Date: Jan 2012 Location: Suffolk VA Posts: 38 iTrader: 0 reviews	I put a new fuel filter,crank/cam sensor,maf,and plugs. It is acting very sluggish. also have Accel Coil pack

January 19th, 2012, 07:19 PM	#6
Huff94 Newbie 94 Mustang 3.8 Join Date: Jan 2012 Location: Suffolk VA Posts: 38 iTrader: 0 reviews	no i didnt mess with the MAF or anything when i swaped to the K&N filter. I just opened the box took the old filter out put the new one in. I just took the MAF out and cleaned it with the MAF cleaner. still running lean.

January 19th, 2012, 07:28 PM	#7
Huff94 Newbie 94 Mustang 3.8 Join Date: Jan 2012 Location: Suffolk VA Posts: 38 iTrader: 0 reviews	sluggish as in problematic. once its going there is power but trying to get it going is like im trying to take off in 2nd. a few of my sparkplugs are black and sooty

January 19th, 2012, 07:44 PM	#9
Huff94 Newbie 94 Mustang 3.8 Join Date: Jan 2012 Location: Suffolk VA Posts: 38 iTrader: 0 reviews	i changed the maf a few months back so i was just guessing that it wouldnt be a bad maf now..when i start the car up cold it boggs down and some smoke comes out the pipes for a min then its all good.

January 20th, 2012, 10:09 AM	#10
Nate3.8 96 3.8 1996 mustang 3.8 Join Date: Jan 2012 Location: Easley, SC Posts: 44 iTrader: 0 reviews	mine was doing the same thing was passenger side upper o2 sensor. now runs good

January 20th, 2012, 12:12 PM	#11
Huff94 Newbie 94 Mustang 3.8 Join Date: Jan 2012 Location: Suffolk VA Posts: 38 iTrader: 0 reviews	yeah thats what im thinking im going to have to change.. im going to take it to autozone to have them read it again to see if its still running lean. see if cleaning the MAF fixed it or not

January 20th, 2012, 02:08 PM	#12
xtreme 2 Hardcore Enthusiast 2001 v6 premium Join Date: Nov 2008 Location: Tulsa, OK Posts: 1,340 Blog Entries: 1 iTrader: 0 reviews	what is the exact code you are getting? which side are the spark plugs messed up on? __________________ Screw it, coming to play with the big boys... 5.4L Vortech COMING SOON!

January 20th, 2012, 07:39 PM	#13
Huff94 Newbie 94 Mustang 3.8 Join Date: Jan 2012 Location: Suffolk VA Posts: 38 iTrader: 0 reviews	i changed back to the stock airfilter and drove 70miles and no code came up. now i just changed back to the K&N . im going to see if it starts running lean again

January 20th, 2012, 07:59 PM	#14
Puffy93 Regular 94 v6 mustang Join Date: Aug 2010 Location: Missouri Posts: 58 iTrader: 0 reviews	try disconnecting your battery for a couple of minutes to reset the computer, the computer is used to the air flow from the stock filter and the increased flow from the K&N is confusing it and making it think its going lean. __________________ 94 mustang 3.8 Steeda Tri-ax, FRPP aluminum driveshaft. Soon to get built 351W

January 20th, 2012, 08:07 PM	#15
Huff94 Newbie 94 Mustang 3.8 Join Date: Jan 2012 Location: Suffolk VA Posts: 38 iTrader: 0 reviews	i did every time i swapped it out..thats why i dont under stand why it says its lean every time i put the K&N in

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January 20th, 2012, 08:27 PM	#16
Huff94 Newbie 94 Mustang 3.8 Join Date: Jan 2012 Location: Suffolk VA Posts: 38 iTrader: 0 reviews	i took out my spark plugs and a few of them are indicating that that cylinder is running lean. im starting to think that all of my problems are coming from some bad injectors. what do you think

January 20th, 2012, 08:38 PM	#17
Puffy93 Regular 94 v6 mustang Join Date: Aug 2010 Location: Missouri Posts: 58 iTrader: 0 reviews	Try starting the engine and spray the area you worked on down with carb cleaner or starter fluid around the area you worked on, if the idle raises then there is a vacuum leak there causing you to go lean. i would do this before you start replacing injectors. __________________ 94 mustang 3.8 Steeda Tri-ax, FRPP aluminum driveshaft. Soon to get built 351W

January 20th, 2012, 09:28 PM	#18
Huff94 Newbie 94 Mustang 3.8 Join Date: Jan 2012 Location: Suffolk VA Posts: 38 iTrader: 0 reviews	will try it __________________ accel coil pack,K&N airfilter,divorce exhaust dumped before rear axle

January 20th, 2012, 09:41 PM	#19
WickedSnake00 MM's king of Neon's 404 - car not found 17.81@87 Join Date: Aug 2010 Location: Diesel Engine Capital of the World, Columbus, IN Posts: 7,376 iTrader: 0 reviews	Yup. Check the major ones before you go replacing injectors. Check for vacuum leaks, check that your MAF is correct, and test your oxygen sensors. __________________ Official Secondhand Snake Build Thread Here Looks Like a Cobra, Sounds Like a Cobra, Tastes Like a Cobra, Not a Cobra. For Sale: P71 Interceptor motor

January 20th, 2012, 10:09 PM	#20
Huff94 Newbie 94 Mustang 3.8 Join Date: Jan 2012 Location: Suffolk VA Posts: 38 iTrader: 0 reviews	whats the best way to test the o2's __________________ accel coil pack,K&N airfilter,divorce exhaust dumped before rear axle

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