computer keeps reading o2 sensor. swapped out twice. rough idle getting worst. help.
#16
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Year: 2000
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ok so back with an update. i got my multimeter in, tested both o2 sensors and connectors. both came back functional. both connectors are emitting power and the o2 sensors resistance were landing anywhere between 5-7 ohms. the video below is one of my exhaust which keeps dripping liquid which i can only assume is coolant. i know with these things you dont want to assume but i'm waiting on a leak detector as well as coolant compression tester to see what is where but i filled my coolant to the suggested top and already, after 2 days of running it while working on it, its down close to the "add" section.
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Year: 1988
Model: Cherokee (XJ)
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ok so back with an update. i got my multimeter in, tested both o2 sensors and connectors. both came back functional. both connectors are emitting power and the o2 sensors resistance were landing anywhere between 5-7 ohms. the video below is one of my exhaust which keeps dripping liquid which i can only assume is coolant. i know with these things you dont want to assume but i'm waiting on a leak detector as well as coolant compression tester to see what is where but i filled my coolant to the suggested top and already, after 2 days of running it while working on it, its down close to the "add" section.
#18
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yea i didn’t notice any steam so hm maybe not there but still need run compression and leak detector because i am for sure losing coolant somewhere. thanks dude.
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doublechaz (01-19-2022)
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Agreed on the other tests.
Sometimes working on a car is a very simple parts swap, but sometimes it is a long process of 10) symptom 20) make a plan to test 30) conclude, repair and test results 40) if not fixed go back to 20.
Sometimes working on a car is a very simple parts swap, but sometimes it is a long process of 10) symptom 20) make a plan to test 30) conclude, repair and test results 40) if not fixed go back to 20.
#20
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im going to post an update over the weekend to show where i’m with all this.
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doublechaz (01-20-2022)
#21
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Please fix that cut vacuum line. Use a piece of fuel line, maybe a couple of clamps. It will take 10 min, will cost next to nothing, you know it's not right the way it is, and it will improve the idle.
You will be able to check something off the list.
You will be able to check something off the list.
Last edited by exasemech; 01-20-2022 at 02:42 AM.
#22
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For me, a dangling wire coming up from the O2 grounded and burned a fuse - however securing the wire and replacing the fuse only removed the code. It may require more diagnosis to solve your rough idle too - (assuming your air filter is clean, and your plugs, wire, rotor & cap are good, and your throttle body is clean) check the other sensers along with the vacuum lines. If all check out, clean and test the injectors
The pins are for the wires
Testing restance in cleaned injectors
The pins are for the wires
Testing restance in cleaned injectors
#23
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For me, a dangling wire coming up from the O2 grounded and burned a fuse - however securing the wire and replacing the fuse only removed the code. It may require more diagnosis to solve your rough idle too - (assuming your air filter is clean, and your plugs, wire, rotor & cap are good, and your throttle body is clean) check the other sensers along with the vacuum lines. If all check out, clean and test the injectors
The pins are for the wires
Testing restance in cleaned injectors
The pins are for the wires
Testing restance in cleaned injectors
thanks this is very very useful.
i have a 2000 so no cap but a coil pack instead but either way it’s getting tested as well.
#24
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update
tested the o2 connector and getting 0.8 - 1.0 reading. i ran both the multimeter test and bought a obd scanner. i posted the obd because it’s easier but i was getting the same reading
#25
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Did you ever reply to this? 4 or 2 sensors?
BTW post-cat O2 sensors on 2000 DO participate in performance.
Sensor 2 can never exceed sensor 1 and certainly can never be 1.0V. Although that value is like WTF is that cause you need a continuous readout to see that it's working. See my graphs previously posted.
ALSO reading all the various threads you have posted on this thing I realized it is a 2000 and you bought it in New Jersey. If it was originally sold in NJ it is likely a California version. (Check the emission label) They have 2 close coupled cats with an upstream and downstream O2 sensor on each...thats 4 total. The downstream sensors do nothing as far as the car running is concerned, they are for the OBD cat check
Sensor 2 can never exceed sensor 1 and certainly can never be 1.0V. Although that value is like WTF is that cause you need a continuous readout to see that it's working. See my graphs previously posted.
#26
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That said:
unless the multimeter has a DVA function it should have been taking a mean reading (because the response time is so slow) and you should be seeing like 0.6V for sensor 1 and 0.45V for sensor 2 (if your cat is good). Did you inspect the length of the O2 sensor wires to look for shorts?
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Did you ever reply to this? 4 or 2 sensors?
BTW post-cat O2 sensors on 2000 DO participate in performance.
Sensor 2 can never exceed sensor 1 and certainly can never be 1.0V. Although that value is like WTF is that cause you need a continuous readout to see that it's working. See my graphs previously posted.
BTW post-cat O2 sensors on 2000 DO participate in performance.
Sensor 2 can never exceed sensor 1 and certainly can never be 1.0V. Although that value is like WTF is that cause you need a continuous readout to see that it's working. See my graphs previously posted.
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i’m going to redo this with he multimeter with alligator clips instead. will post update. it was quite difficult to see exactly what was happening with the pins. will be back