Computer question

[97ExplorerV8AWD]

I've read that Ford didnt flash the serviceports of many 5.0 Xs ECM correctly. Would this cause the CEL to not work? The bulb works, it glows on startup. I feel my Oxygen sensors may be bad. I'm going to try testing them, though that is a lot of work, if possible (four wires). I had a sparkplug wire problem a month back and the truck would missfire, but no check engine light, shouldnt it have come on.

If I do end up changing my O2s whats the best way to do it, the 3 rearward ones are impossible to get to. It looks as thogh theres an access panel from the passanger compartment, or do I need to drop the exhaust?

 

[section525]

You shouldnt need to drop the exhaust. Use the passenger side wheel well (take out the plastic part) and also just use plenty of extensions and elbows! As far as your computer.. it does sound fishey. I'd disconnect one or two O2 sensors and drive around for a few miles. See if it comes on.

 

[Robert]

I used my O2 socket and ratchet on my two driver's side sensors and a wrench on my two passenger side sensors. I have a body lift which did make it a bit easier to get to them though. I had all four changed out in about an hour with no skinned knuckles nor cussing.