P0171 Buick - 99 lesaber

Question

P 0171 car has ruff idle and does not start when warm also falls on its face when u give it full throttle

Answer 1

These cars are know some having intake manifold issues and intake gasket leaks. P0171 can be an intake leak which is very common

It is at least 3 hours of labor to replace lower and upper intake gaskets, (in alot of the cases the intake manifold may be cracked or let in coolant into the engine. Use the orginal intake manifold from the dealer and oem gaskets.

there are two designs for the intake manifold all metal (over $500) or the plastic one ($200 or so)