Question about CEL (Bank 1 Too Lean At Idle)

[07CosmicMS3]

I have an 07 MS3 with HKS cbe, HKS intake and HKS bov.....I'm throwing a CEL about every couple hundred miles saying *bank 1 too lean at idle*. Is this a problem with the HKS intakes or is it something else? Also, if it has anything to do with the fuel pump issue what do I have to do and where do I get the parts? Thank you

 

[bgibb68]

isn't the bank 1 too lean the #1 O2 sensor???

 

[mr_mazda329]

Bank 1 is the primary o2 sensor. The one in the stock down-pipe before the cat

 

[bgibb68]

Bank 1 is the primary o2 sensor. The one in the stock down-pipe before the cat

thanks for confirming...i thought that was the one i got when i forgot to hook up the damn thing

 

[07CosmicMS3]

anybody know anything?

 

[jam_asian85]

try cleaning the MAF sensor

 

[07CosmicMS3]

i put my stock airbox back on and it hasn't thrown the code since......any thoughts?

 

[red07]

I would check the HKS intake and see if there is an air straightener right before the MAF sensor hole. The air straightener will probably look like a baffle, or some crisscrossing pieces of plastic or metal.

If your intake has this, then chances are the intake diameter is not the same as the stock airbox assembly diameter right @ the MAF location. The MAF sensor is very sensitive to airflow velocity, and diameter changes affect the velocity.

If your intake does not have this, then the MAF is reading turbulent airflow and throwing that code.