Greenbird97

iTrader: (20)

Hi,
I just recently put on an LS6 intake. I also ported and polished my maf (removed screen and center dividers like ls1howto.com shows). Now my idle is 100-200 rpms lower than normal and I have a "system too lean" code on that is triggering my check engine light (I had autozone pull up the code but i can't remember what the P code was). Could this be caused by what I have done? Would a simple tune fix this? Or is this something else? By the way, this problem started immediately after the installed items were put on the car.

hitmanws6

iTrader: (20)

i love it when people descreen the MAF and wonder why they are running lean and have idle issues. get yourself a new maf

JeaneZ28

iTrader: (3)

I have a descreened MAF and no problems here.

Greenbird97

iTrader: (20)

i actually descreened it several months ago without any ill effect, would porting it really cause it to lean out that much? Other people have done it...

hitmanws6

iTrader: (20)

the P/P MAF is a shot in the dark. you might succeed and gain some power, or you might fail and have the issues you are having. the descreened MAF temporarily leans the car out, adding more power. but eventually the PCM compensates for the extra air and the A/F ratio becomes the same. the screen is there for a reason. the stocker is good for around 450rwhp, after that you should switch to speed density. get a new maf and see if it goes away

jrm1493

The descreening probably won't do much but porting it out means you have changed the reference area and all the material you took off is now allowing unmetered air through. The computer is respoding by dumping all the fuel it can into the engine (the MIL will illuminate when it was gone 25% rich on the long term trims I believe). You *might* pick up a bit of performance part-throttle with this trick, but you've probably lost open-loop (WOT) performance because it will go full rich on you when you floor it. Good for engine longevity but bad for performance.

The only way to fix it via a tune would be to change the MAF tables (basically tell the computer that the MAF now flows more air for a given current that is being passed through the wire). I guess you could have the codes tuned out but that is a bad idea because these are not true emissions codes; you want to know when you are rich/lean because it means something is off.

Best bet it to just "unport" the MAF (which probably means buying a new one). The stock unit should be fine for your mods.

Greenbird97

iTrader: (20)

I found what the error code was. It is P0174. This is a lean code right, not a rich code?

majeskyb

iTrader: (1)

My car gave me the same code a few months ago. Caused stuttering problems and felt like it was down on power. My problem was a vacuum leak- my PCV hose had a hole in it right by the intake manifold. fixing the leak took care of the SES and my power problems. Might be different for you, but since you said that you just swapped your intake, you might want to double check your vacuum lines.