A few months ago the SHO developed an intermittent studded at idle, even stalled a few times. I had been getting an O2 sensor fault (bank 2 sensor 1) so I replaced it with a new one that I've had on the shelf for a year or so. The stumble didn't fix and remains intermittent, maybe 1 of every 3 times I drive. Once I got a code indicating a fault with the Evap system but sadly I don't remember the specific number nor the exact fault. I do know that I get a HUGE vacuum when I refuel, so I assume there is an issue with venting in the tank.
Within the last week or so, Ive gotten P2195 and P2198 (one o2 is stuck rich and one is stuck lean). Ive checked for loose and cracked vacuum lines under the hood and have checked the connectors to the 02 sensors for chaffing and that the connectors are tight.
Any idea where I should start checking/replacing stuff? I'm hard against going to the dealer, they will just charge me $100 to do nothing more than I can do on my cell phone and start replacing components, witch i can do in my driveway.