llamatymer

Hey guys, my car is throwing a couple of codes sys too lean 1, and 2. Does anyone know how to fix this or what causes it?


Thanks guys,

-Matt

avexhype

do you have cats on ur mid pipe?

llamatymer

No, I have mil's, and the rear o2's are shut off with the xcal2 i'm not sure if I need the mil's anymore. Also I tried putting it back to the stock tune, and it was still throwing the codes. It's weird when I first install the tune it doesn't do it, but like 20 mins later they come on.

Thanks,

-Matt

jwog666

cats or not it wont matter, those codes are for the upstream sensors. the light goes off after u install your tune because doing that erases all codes. clean your maf, if its dirty it will not read the volume of air correctly and these codes will be set. if that doesnt fix it check for vacuum leaks or any air intake leaks

llamatymer

Ok, I'll give that a try, and thanks for the info.

mustangman03

It also could be your fuel filter or the fuel pump itself. Have you ever changed your fuel filter?

tbirdscwd

I had the same codes when my fuel pump was going out. But then again, I was throwing low fuel pressure codes too.

cliffyk

All good suggestions,

Here's what the shop manual says about those codes...

FixFalcon

Great link, thanks!

WhiteFoxGT

Do the simple checks.... You dont hear any exhaust leaks do you? Leaky manifolds or collectors will set lean codes.. You probably have a vacuum leak.. Spray some 2+2 around the intake where it bolts to the head, and around the tb/plenum + vac lines. If you hear a difference in RPMs when u spray a certain spot, theres the leak.