[Shop-talk] PO174 - PO176 OBD CODES

[Mullen, Tim]

john niolon wrote:
>
> from my googling it seems that it 'might' be a dirty MAF
> sensor or vacuum leak or leaking hoses etc figured I'd
> start with the MAF sensor.

Do you have a K&N type of air filter on the truck?  If so, over oiling
(or even not over oiling) the filter often messes up the MAF.  If you
have an oiled filter, I'd start with changing that out for a paper one,
and  cleaning the MAF.

Otherwise, I'd look for a vacuum leak.  First do the normal checking of
all hoses for cracks and tight seals.  If that doesn't find any leaks,
you could search for the vacuum leak is with an unlit propane torch -
especially the type with the torch on the end of a hose.  Turn it on
very low, and, with the engine running, move the unlit torch near of the
possible sources of a vacuum leak.  The engine should change RPM if/when
the propane is sucked into the leak.

Tim Mullen