98 Chevy Tahoe, Codes P0308 and P0161

I've got a 98 Chevy Tahoe with about 125,000 miles on it. 350 TBI engine and auto tranny. A few weeks ago it starting running rough and the SES light came on and frequently blinks as well. I took it to the Azone to have the codes ran, and it came back with the following:

P0308: Cylinder misfire detected-Cylinder number 8

Probable causes listed as:
1 - Ignition system fault-spark plug(s), ignition wires, coil
2 - Vaccum leak
3 - Injector fault
4 - High or low fuel pressure

P0161: H02S 22 Heater condition (Heated Oxygen Sensor Bank 2 Sensor 2)

Probable causes listed as:
1 - Oxygen sensor defective
2 - Poor connection at oxygen sensor
3 - Check circuit-fuse

About 1 yr ago (4,000 miles) it was running funny, and the distributor drive gear turned out to be the problem. Before having a shop diagnose that and repair it, a I had replaced the distributor cap, rotor, spark plugs, and wires.

Any advice on where to go with this?

Thank you,
Danny

Did you use AC Delco parts?

GMs don't like aftermarket parts.

Acertain that the plug is firing, then check out the other possible causes for the misfire as well as the O2 issue.

Good luck and keep us posted.

No, I did not use AC Delco parts, but the truck has run fine for about 1 year(4,000 miles) with the Autozone stuff I installed. I'll pull the plug on cyl #8 and see if it is sparking.

I am such a pessamistic bastard. This is a spare vehicle for me, so I wasn't in a hurry to get it fixed. I figured it was something major and would cost a bunch, so I was in denial and wanted to wait until after Christmas to deal with it. Well, I popped the hood this morning and found the number 8 cyl spark plug wire had fallen off the plug . Oh well, all is fine now and I feel like a total dumbass for not just giving it a quick lookover when it first started acting up. It is never anything that simple right? LOL.

Danny

Yea...we've all been there.

Sometimes, even a blind squirrel finds a nut!

What about the P0161?