94 s10 4x4 with over 100,000 on it. On top of that we're a military family moving out of the US in 6 months and this truck isn't coming along. Its got codes ( 02, map,egr...) and we've had electrical nightmares too. I just need 6 months out of this thing is what I mean. Went for smog test and wasn't able to maintain high idle to even take the test. Flucuating idle so test was aborted. On occassion every few months it does get to where it feels like it wants to stall. I fix this by flooring it down the freeway. Like it's got some kind of abstruction that needs to be blown out. Other than those times it runs fine. To me runs great for a truck 6 months away from it's last start(by me at least). I took it to shop told them just get it to idle within test specs to take the freaking test. I'll worry about failing after I've failed you know. I asked specifically if o2 would cause the idle flucuation and was told no not enough to cause it to get aborted test. 2 days later I'm told has burned out it's o2. They want to START with doing that then try to test it again (at added $59 test fee). I can get free retest from the place it got aborted test. They want $210 to do the o2 and I already owe $90 for the hour he has spent confirming the bad o2. I pretty much knew it needed that when I handed over the keys along with list of codes o2 being one of them. I asked if that would cause idle problem and was told no. Don't get me wrong I understand clearing those codes would be place to start but is the o2 the one to start with. We're not mechanics but thanks to this truck we've learned hands on quite a bit. Ok so after all this I have 2 main questions. Is the o2 where they should be looking first ? And how difficult is it to change out if we did it our selves ? I would like to avoid thier labor fees and $59 smog test I can get else where for free. The codes were 107 map , 117engine coolant sensor, 123 throttle position sensor, 139 O2 sensor, 300 EGR valve.
Thanks to anyone with any advice or suggestions

cmr29sun