fuel problem

[Ldub]

Prolly intake gaskets...

Or other un metered air entering through cracked/loose vacuum lines etc.

Get out there under the hood with a can of starting fluid (ether) or other VERY flammable spray can (carb cleaner being another), & spray here & there around the engine...like under the intake, by the injectors, etc.

Listen for an increase in idle speed.

, & be careful playing with flammable stuff...

[fildigger]

Good call with the easy start fluid sprayed around both intake manifolds (they are prone to letting go!!!)

I assume you have had it on the Diag' tool ?...why leave it for a year?..guess it can't be to bad if it is still running acceptably for you....although running lean is never a wise thing for long term reliability