to lean??

[JPstealth]

ok, heres my dilemma... my car is a 00 GT with 60k miles. The engine light is reading lean in bank 1 and bank 2 and i cant figure it out. The car also idles erracticly.

it has C&L intake and maf, reichard intake manifold, full exhaust and a few more normal goodies.

so far i have:
cleaned the K&N filter, the entire intake, and MAF.
I have also checked for vacuum leaks and found a couple small ones which i fixed.
I changed the IAC
put injector cleaner through it

car seems to run fine when driving but i did notice a slight whining in the back of the car at idle, could this be the fuel pump going bad? would that contribute to a poor idle though?

any other suggestions?

 

[the98stang]

lean codes could be triggered by a faulty o2 sensor.

 

[urban96]

could be the aftermarket MAF

 

[Ken01GTvert]

When did you start throwing codes? Have you had a tune since you added the C&L intake, MAF and K&N combination? I was throwing codes when I went to that set up. I didn't want to get a tune so I replaced the C&L MAF and K&N with the stock MAF and Filter/housing with the rubber nose pulled off and then no more codes being thrown.

 

[SilverBullet00]

I have heard a lot of bad things about non FORD (or SCT) MAF's I would pull it off and try to run the stocker..

 

[urban96]

a custom tune would easily cure that

i havnt heard many good things about c&l mafs. they with the 5.0's it seems to be hit or miss with idle problems

 

[JPstealth]

yea, the car has no tune. This maybe is an excuse to go get one Other wise, ill see if I can get my hands on a stock maf and switch it out and cross my fingers.

 

[joshheat25]

I have the same C and L intake and I also have an aftermarket tb and upper plentum and I have o/r exhaust when I took it to get it tuned it was over 25% lean on startup. I was throwing codes just like you wondering wtf. I had a hand held tuner and still was lean. I got a tune and now I'm fine! either get a tune or put the stock stuff back on.

 

[Stormer]

I hate to admit this... but it may help you;

I was having a similar problem with my 2003 GT, I also just turned over 60,000. I have a MAC 85mm Cold Air Intake system and when I put it on my engine started throwing lean codes in both banks and had difficulty starting. I cleaned out my sensors checked the vacuum hoses and had a diagnostic run and it still didn't fix the problem. I put the stock box back on and my codes went away. After a few weeks it crossed my mind that it had been some time since I had the fuel filter changed. (supposed to do it every 12,000 miles) I took it to the shop the following day and had it replaced put my CAI back on and have been running almost a week with no problems and a lot better power!

 

[9646gt]

Tune would be best bet, if the MAF is clean and all it should fix it. I don't think it's a faulty 02 sensor , wouldn't that throw a code?