Originally Posted by kscoyote
I drove a company crown vic for 5 years, with the CEL flickering. Finally took it in, it was an oxygen sensor.
Ok and? I have serviced several cars with the CEL on and guess what? It wasn't an 02 causing it. That CEL will stay on until the ecu reconized a change in the parameter of that DTC. Just because yours was an 02 related, doesn't mean they all are. There are several different DTC's both emissions and non emissions related. Hell she can have a transmission issues(automatics) that can throw a code.
I had a kid bring in his v6 Mustang with a cel on for a month. What did I find? Maf was dirty, TPS sensor wasn't fully plugged in and the air vent hose on the drivers side valve cover was loose.
If it's the fuel cap, it'll go away . . .
Only if you tighten it. If you leave it loose the ECU will reconized it is not pressurized and it will stay on. That is why many auto manufacturers have the EVAP system. I see this alot at the dealership as well.
it could be something else, but you'd have degraded engine functionality. It wouldn't behave normally.
Not really. A dirty Maf can throw this and you wont see a decrease in performance, same with the Secondary air injection system on the engine as well, you won't see any chance in performance, Along with the EVAP system and the valve and charcoal canister, ECT sensor can do this, IAT sensor can, even the VSS can have a fault, catalyst below efficiency(converters).I can go on and on, but don't assume it's tyhe 02's because no change of performance will only be associated with the 02's
If it behaves normally in every other way, 9:10, it's an oxygen sensor.
I wouldn't worry about it -take it to the dealership for your next oil change, or autozone to run the code, but it's generally not anything big at 40,000 miles.
Again, I just showed you what some of the issues are that can behave correctly that I have found on cars that were not 02 related.
Again, I wouldnt listen to this guy as I have seen people follow that guidance, and I handed them a bigger bill for something they could have fixed sooner. Look at it and you KNOW what it is. It could be anything, and that is why they created the OBD II