P0171, P0174 and scan tool readings

micky > wrote:
>That's good. There must have been some vacuum leak, and I suppose it
>will reappear**.

Right. And as someone else here pointed out, it's likely on the intake
gaskets because they are a known problem on those engines.

>What I should do is use the scan tool to get the same sort of readings
>when it's working right, and maybe I can find one or more values that
>are different from when it was working wrong, and maybe if/when it
>starts working wrong again, someone can sit in the car watching just
>that/those values, and when I fiddle with the right hose, or blast the
>right 02/fuel sensor, he's see the change and tell me.

Well, just watching the readings should be sufficient. If you manage to
block the leak or get propane into the leak instead of air or the like,
the numbers will change immediately and obviously and then return back
once you remove your hand or the propane torch from the leak.

But you also know that the intake gaskets are bad, and if they aren't
causing this problem, they are likely going to cause another.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."