2.5L ('98-'01) 2000 2.5L Auto Pulsing Vibration at All Speeds.

[HighMileage93]

Dad's Ranger started acting strange all of a sudden last night. Pulsing vibration at all speeds, downshifting different than before, stopped at light and idle dropped way down and rough, oil pressure guage dropped with needle wag, light turned green and could barely get it to take off. When it finally did take throttle again it was abrupt and spun the tires. Did this the rest of the way home. This morning, started and idle went high and took a good while to come down some but not to normal. Seems like delayed shifts too. WTH? No check engine light and no stored codes.

 

[Uncle Gump]

I moved this to the correct engine forum.

Most times when you have unstable idle it can be related to a vacuum leak. Depending on where it is... other symptoms can also be noted.

I would pop the hood and take a long visual inspection of all vacuum hoses first.

 

[HighMileage93]

Okay, it just now threw a trouble code.
P1132 - Lack of Upstream Heated Oxygen Sensor Switch, Sensor Indicates Rich Bank 1.

 

[Uncle Gump]

Doesn't mean the HEGO is bad...

Could mean a vacuum leak making the sensor trigger the code.

 

[HighMileage93]

Truck has new plugs, wires and a new upstream O2 Sensor. Going to check vacuum lines for sure.