Pretty much every O2 sensor code just came up NEED HELP!!!

[cyclescientific]

Hey guys,

On my way to work the check engine light came on. I pulled the codes:

P0133 - O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)
P0135 - O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
P0141 - O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
P0155 - O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
P0161 - O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 2)

Now I have a hard time believing that suddenly all 4 of my O2 sensors failed so I'm guessing it's electrical but I was hoping someone could lend some advice as to a good place to start. I drive ~2500 miles a month so I need to fix this ASAP.

Thanks in advance guys!

***EDIT*** Forgot to mention - I check the 20amp fuse this morning and it's fine so at least (or unfortunately) that is not the problem.

[okmech1]

Cycle,
I looked in my 2001 Passport manual, I don't know what year yours is, but this info should be pretty similar:

All 5 of those codes have to do with the heater circuit. Looking at the prints from the "o2 sensor heater fuse, that feed continues to all 4 heater sides of the sensors. (The heaters act to quicken the time the sensors get hot and can function to give info back to the PCM). If all 4 sensor pop a code, that means that the PCM is not getting the voltage signal from ANY of the sensors. There is a toubleshooting tree for each of those codes, that mainly looks at connection and wire integrity for each sensor, but my thinking (and mind you this is just a logical guess looking at the info) being that you checked the fuse and it's good, there is probably an open in that line between the outfeed side of the fuse and the first sensor (should be bank 1 sensor 1 - which is the one in front of the catalytic converter on the passenger side). You might want to be certain the fuse is good not only by visually checking it, but also putting an ohm metter to it and verifying resistance or continuity.

If that fuse is definately good, you are going to have to track down to find out where the voltage is getting lost (broken wire, bad connection at the PCM). It's hard to say by the print if the sensors are in direct series (i.e. if one is disconnected, all the rest will have no power) or if you disconnect one, the others will stay powered.

If it helps, the wire color coming off of the fuse to the first sensor is red/blue.

Hope that gives you a start.

Mark

[cyclescientific]

okmech1/Mark

Thanks for the info. It's a 2002 (3.2L RWD). I'll check that out tonight. I'd guess you're probably right as I reset the code and it takes a while to come back - likely a loose connector or wire that goes in and out. I'll be sure to post any "results"

cheers,

James