Mass Air Flow Sensor

[Wasserja]

2005 ZHP with 143,000 mi. has begun to stammer after cold start and will continue to do so until the engine is warm. Idle will search up and down 200-300 rpm. Idle seems to settle down on the low side once the engine reaches normal operating temp. Already replaced nefore the current problem developed: fuel pump, plugs, coolant thermostat (3x), transmission thermostat. Tech advises that computer check indicates faulty mass air flow sensor. Please; your comments and suggestions. Thank you.

[ZHPizza]

Definitely sounds like it could be the case. If the tech pulled the diagnostic codes then that would be about as accurate of a diagnosis as you can get. Did he give you the exact code or can you pull them yourself?

[az3579]

Unplug the MAF and see if it runs any better. It's a quick way to see if it's an obvious problem.

Sent from my Pixel using Tapatalk

[Newjack]

Would a faulty MAF cause the engine idle speed to dip below norms and bounce back up?

[Wasserja]

Definitely sounds like it could be the case. If the tech pulled the diagnostic codes then that would be about as accurate of a diagnosis as you can get. Did he give you the exact code or can you pull them yourself?

Will try. Thank you.

[Wasserja]

Will do. Thank you.

[az3579]

Would a faulty MAF cause the engine idle speed to dip below norms and bounce back up?

A friend of mine had this issue with his bad MAF. A bad unit could cause rough running or driveability issues.