P0170/p0173

[john.m]

santa fe 2002 2.7 4wd (LPG converted)
Got the above two codes, I have changed the MAF worked fine for 2 month.
Codes back again.
Am i correct in saying that it cant be (fuel pressure/pump, injector fault) as it lpg.
I did find a small leak on the EVAP canister purge valve, fixed this,still got fault.
And i think it cant be o2 sensor as the fault is on both bank 1+2

Any thought would be grateful.

[Rsquared]

Welcome to the forums.

Here is a list of possible causes...Intake leak, AIR system, fuel pressure/pump, injector(s),
EVAP canister purge valve, HO2S

And it could be a fuel pressure issue. Your lock off/vaporizer can get plugged and cause lower fuel pressure.

[john.m]

Can it still be (fuel pressure/pump, injector, lock off/vaporizer ) when the car is running on Lpg
which has its own injectors etc.
I have checked intake air leaks but found none,
What do you mean when you say air system. (sorry for being a bit thick)
Ps
if it was a faulty O2 sensor then the fault would not be on bank 1+2 unless both O2 sensors were faulty.Or am i wrong.

[Rsquared]

If there is a restriction in the fuel system, it doesn't matter what kind of fuel.

[john.m]

when you say lock off/vaporizer can get blocked, do you mean the PCV valve

[Rsquared]

when you say lock off/vaporizer can get blocked, do you mean the PCV valve

No! There should be a LPG valve before the throttle body.