O2 and VSS codes

[jwhowes]

Codes for both N2 upstream O2 sensor and VSS sensor just came on. Its only intermittent and when its cold in the morning. All 4 sensors are brand new and just passed Cali smog. There is no issues otherwise. Runs fine and no change to idle or anything. Plus like i said it resets by the afternoon and it doesn't happen everyday. If anybody has any suggestions it would help. I just bought the Expy about 3 months ago and thos is the only issue besides the rims i need to change.

James
2001 XLT 5.4 240k miles

 

[docraymund]

Some say you should only fit OEM O2 sensors otherwise check the wiring all the way up to the ecu for any short.

 

[jwhowes]

I checked the wiring and all 4 are O2 are OEM. Came on again but came off as soon as i filled up with 91 octane. The wife put in thencheap stuff while I was gone. Could Cali's bull crap winter blend fuel also be meesing it up if it started to clog a injector.

 

[docraymund]

I doubt it. If an injector gets clogged, adding 91 octane won't cure it. You can continue with that blend but if the problem goes back, then try checking connectors for looseness or poor contact from sensor to ecu.