Thread: Fluctuating RPMs 05 GP

Where should I look for the vacuum leak at? And I did plugs about 20k ago but not wires. And I should replace fuel filter as well.

I would start by looking at all the vacuum hosing and the rubber connectors for easily visible flaws. Failing that, you may need to pray some carb cleaner at it while the engine is running to see if the idle changes when the area is sprayed. A very common spot is right off the lower intake manifold, passenger side - there is a rubber T there that dry rots easily.

When you changed the spark plugs, did you make sure they were gapped properly?

Yep, I checked them before I installed them.

Finally got it hooked up to scan tool going down the road and found out the o2 sensor I just put is going ape crazy. We're gonna check wiring and if thats not it get a warranty on the sensor. But, never threw any codes?

It's a good idea to make sure you use Delco sensors. Cheaper ones can cause issues.