Well, i searched the site with for my code and how people have fixed it (p0175) and all i can come up with is this:

1. Clean MAF sensor - DONE
2. Check for vacuum leaks - done? ive sprayed brake cleaner on/around the ends of vacuum lines on the block/manifold area

anything else i could check? My cats are hating me right now driving with this code, they pop and crack while driving around.

(BTW: Running lvl 3 on evolution with 91-92 octane, no custom tuning, just lvl 3)

 

Maybe its the tune? Lean conserves gas, Rich is fast?

 

i would check for excessive fuel rail pressure. could be the regulator. or a restricted return line.

 

Your o2 senors may be bad. i had the o2 on my driver side go bad and it caused all 4 cyl's on that bank to run very very rich.

 

I understand with the higher octane fuel the timings been advacned some, but where talking very rich here.

Fuel pressure was normal, dont think the regulator is bad, but ill check that with a vacuum gauge later. Return line i havent checked yet.

I just replaced the front 2 o2s less than 10,000 miles ago ( 143xxx on the clock ) So im thinking its not those.


any other ideas/hints? im started to think its just my truck & the tune... 12.9 MPG in the city running 91 edge lvl 3 /14 MPG highway running 91 & edge lvl3

 

Thats not very normal mileage for these engines...Humm id say set the tune back to stock and see if it fix's it. humm other than that i dont really know what would cause this.