dsmky@69

Hey guys. I am getting a p0175 code and 0430 code along with fuel trim running -16 on bank 2. I have replace plugs wires o2 sensors injectors. I think I have a vacuum leak. Anyone have any experience in this?

tech2

what year and engine?
on a maf fuel metered vehicle a manifold vacuum leak would lean out the fuel trim not make it rich...you system is cutting fuel not adding it. an exhaust manifold leak may lean out the 02 sensor reading

the po430 code is setting as the fuel trim is pegged rich causing both pre and post 02 sensors to switch at the same rate. fixing the p0175 will fix the p0430...but don't leave it for too long or the overfueling will kill the cat.

I would check the fuel trim on both banks...if both are cutting fuel the problem is something that effects both banks....flex fuel sensor askew. bad maf. high fuel pressure.
manifold vacuum leaks only show up at idle and are gone at higher rpm. check the fuel trim at idle and when held at 2500rpm....if its adding at both rpm...its not a vacuum leak. if it corrects itself at 2500rpm...it may be a vacuum leak

dsmky@69

2008 5.3 flex. I have changed maf sensor. It is only running rich on bank one. I will try check at 2500 rpm.

tech2

then check the 02 sensor voltages...if its not switching properly....replace it.

dsmky@69

I have changed them and the up stream on twice just to be sure. Thing is driving me nuts. I am afraid it’s something internal to do with the lifters