ok guys i have a 98 Bonneville 3800 n/a. im having a couple issues i think are related. the car idles very high 1500-2200 rpms until the thermostat opens then runs normally around 800rpms. in addition to that sometimes when the therm opens (closed loop i think) the engine starts stuttering and missing and sometimes dies, then you can fire it up and it runs perfectly other times it dies with no warning and then you can start it back up and runs perfectly. it threw a PO306 cylinder 6 misfire and PO101 Maf i have gotten a o2 sensor fault with the others but not every time. the maf tps iac have all been changed recently. any help would be greatly appreciated! very desperate here thank you!

Are you still getting those codes or have they been cleared?

They have been cleared currently. They have been cleared three times

Disconnect your MAF sensor and see if the idle changes.

We just had another member here replace his MAF sensor and it still idled weird. He replaced it again and it cleared itself up. Stay with the AC Delco MAF sensors.

Ok just started her up and was idleing at 1700 unhooked maf and the engine stumbled then shot up to 2200 rpm no check engine light

Disconnect it while the engine is off, then start it.

Idles poorly but right around 1000-1100rpm

Does this indicate the maf is faulty?

If you were getting a check engine light for the MAF, then its a good probability.

Ok I appreciate your help I'll do some more work and keep you posted!