02 sensor

Hi all, hoping some one can help?
I have troubles with a 2003 Jeep TJ, 4L,
Had a check engine light come on last winter (P0141) but only came on when it was cold outside,
Deleted the code and it was good for a few weeks. As warmer weather came, I no longer was getting the code, two weeks ago it came back. Thinking it was the 02 sensor I bit the bullet and got 4 new ones.
Figured if I was going to change one lets change them all, (the old girl turned 200,000 miles).
After getting them all changed, I cleared the codes. A day later the code came back, by day two I got more codes, as time goes by there are more, getting ready to shoot the sucker.
I now have ... P0138, P0141, P0158, and P0161.
Not sure how to test the wiring, have done some research on this and found if you do it wrong you can fry the PCM.
Anyone got any suggestion’s, as a good place to start? I do not do well with following wiring diagrams to get the heater wires, they should be the white ones I think ? thinking I have a bad ground some were ? or broken wire with the one off the start, Bank 2 sensor 2, then made it all worse when I changed the other one’s ?
Hope this gives someone enough info to find a solution.
Thanks Jerry

Did you use OEM parts ? Chrysler vehicles don't play well with non-oem sensors.

Yup got NTK sensor's, will have to check the wiring for ground ?

Check the o2 heater fuses in fuse box to see if they are blown. Odds are they could be blown very rarely do all four new sensors have bad heaters in them. If not check the wiring with a volt meter for voltage at the o2 conectors (those codes are for the heater circuits for all 4 o2 sensors).

checked the 02 sensor bank 1 sensor 1 + bank 2 sensor 1, they were the easy ones to get to , checked the ecm side of the plug got 13 v and a ground, checked sensor side when hot and got continuity on the heater, haven't got to the other two as they are harder to get to. Need to get some back probes to check the plugs connected and get signal return, i did get 4.16 v for a signal coming from ecm.
Not sure if this has anything to do with all this but the clutch safety switch quit as well, ( thinking about the time all the codes started )don't need to depress clutch peddle to start ?

Yeah you should have to press clutch pedal to start it it would not hurt to check clutch switch on clutch pedal bracket up under dash near top of pedal arm. Odds are it shorted out so look for a melted conector etc. ... the connector for switch should be on the bracket. Also check the wiring by ecm and down to o2 sensors that voltage of 4.16 doesn't seem right could be pinched or bare wire running to sensor causing this as mice squirells do eat wiring.

Oh one other thing there should be a ground wire on framerail on either side for the o2 sensors. check to see if it is broken or corroded.

Thanks, will look at the wires, the readings were for the bank 1 sensor 1 and bank 2 sensor 1, all the codes point to sensor 2 on both banks, haven't checked them yet.

Just checking info... you used NTK sensors. are the part numbers
B1S1 23139
B2S1 23138
B1S2 23142
B2S2 23141
if numbers are correct check to make sure the sensors are in the corresponding locations and connectors are plugged into the right sensors.

do the easy first then move on to the complicated...

Yes i got the right ones, already checked the orientation, that was my first guess, even checked the plugs to make sure they were plugged in all the way. Changed the spark plugs, looking to see if maybe there was a bad one or two ? or maybe a injector not working right ? plugs were clean no sign of any fowling. Even changed the MAP sensor as it was about the only sensor not changed. Finely got the back prob pins, so i will be able to check the connections plugged in to see if they are getting a return signal. Got power, reference power and ground, the best i can tell.

Still wounder about the clutch safety switch, got a new one on order as it does not work, will be interesting to see if maybe that has some affect on all this,

Will post the readings when i get them, maybe someone can see a problem i am over looking ?

Pulled the clutch safety switch out to test it, it tested ok, then I checked the lead wires it hooks to and there is no power. With the switch removed jeep will start!!
Anyone got any ideas where to go from here, not sure how it is back feeding to close the circuit? or does the switch just close the ground?

Jerry McGillis wrote: Pulled the clutch safety switch out to test it, it tested ok, then I checked the lead wires it hooks to and there is no power. With the switch removed jeep will start!!
Anyone got any ideas where to go from here, not sure how it is back feeding to close the circuit? or does the switch just close the ground?

Should only be hot in start. Did you replace a "missing" fuse in the fuse block right before the clutch safety switch quit working?

Thanks Matt, the diagram is help full. The only fuse i have moved is the one for the interior lights as i had the doors off a week ago. Have read about the bypass fuse, will check if that one is there !

all the codes are for high voltage on the heater circuit. this makes me suspect a ground wire issue on the 02's. the voltage on the 02 heater circuit is a 5v bias voltage which is pulled down by the pcm through a ground. you should not have more than 100mv on the ground wires. because you got the codes after changing 02's, a ground wire must be open. its a lot of work but if you put the old 02's back in and the codes do not appear, you have a bad new 02... it does happen. I'm thinking its the B2S2. if you have the ability, you can graph the 02 voltages. they should show steady at 5v at idle with the current error codes. increase the engine rpm, 1500 or so, the exhaust gases will heat the 02's up and the voltage should drop. if it drops, look closer for an open ground. all four new 02 can't be bad, that would be really really weird unless you got the 02's from a fly by night supplier.

Thanks , got the clutch safety switch fixed , my mistake of putting a fuse in the over ride by mistake . For the o2 sensor yes its is only the one acting up, try to remove the ground wire on the side of block that I think are the ones for the ecm , not much luck with the stud they use , but haven't got any codes since. Got the stud out today , cleaned the connections and put a bolt back in it , hopping this will fix the problem .

Well I believe I have the problem solved. When I unpluged a sensor to check ground ,power then plug it back in , erased the codes that one sensor never shows a code .Never cluded in on that til the other day. Unpluged
the last one checked the plug , plugged it back in cleared the codes.
Haven't had any more codes on any of them.
Don't understand how that can solve the problem, but I am going with it .

Corrosion in the connector could have been the issue then it would seem