High voltage 02 sensors

Just replaced both 02 senors not 2 days ago, now my light is back on and it is reading high voltage to the 02 senors. it runs fine on the highway but when you stop at a red light it will start missing and stalling. I have done some searching, what i need to know is, what will cause the high voltage reading.

2000 xj

later Heath

Check the wiring to the sensor(s) to see if it is damaged. Not sure about new jeeps, but older ones, wiring has been know to have unfortunate encounters with the exhaust manifold:tears: causing shorts. The heater voltage wire may have shorted to the signal wire.

From a noob:

I just replaced FOUR 02s (CA emissions) on my kid's '00 XJ Sport. My worry about the hivoltage comment above is... are you sure you've got the right replacement sensors?

I spent far too many hours trying to get the right sensors at the right price. The 4 OEM sensors (factory installed) had all different part numbers. Most common on-line cross references offered Denso or Bosch parts that had different upstream numbers but the downstream sensors were the same. Now the downstream sensors might be the same sensor but the wire lengths are different!!!! One Taiwan supplier offered the same part number for all 4 sensors! Even "good" supply houses offered 3 or more Bosch numbers for the same application.

Anyway after all this diligence I went with the Denso product and successfully cleared all the codes BUT one of the downstream sensors needed longer leads and it was a stretch to make the connection.

Bottom line make sure you've got the right sensor, installed right, wires not all twisted or nicked from boltup, and routed safely. Its a jungle out there... too many (poor) choices.