Very rough idle, PO161 code
#1
Very rough idle, PO161 code
Well it's been a while since I've broken my truck, so it's good to see you all again.
About two weeks ago my truck started idling really rough. The RPMs drop to 500 then surge up to around 1100, then start over again. My truck has 130k on it and the oxygen sensors have never been replaced so I thought that was most likely the problem. Replaced the two primary sensors and the truck still idles horribly. I've been told all sorts of things: PCV, TPS, O2 sensors, bad cats, IAC, etc...
So I scanned the codes and came up with a PO161, which is some sort of malfunction in the downstream driver O2 sensor. While doing some inspecting around there, I noticed that the wires on the downstream passenger O2 sensor have worn through and are possibly grounding on the tranny mount. That one obviously needs to be relaced.
So I want to know if I can expect the truck to run fine after replacing the back O2 sensors. If not, what should be the next step I take?
About two weeks ago my truck started idling really rough. The RPMs drop to 500 then surge up to around 1100, then start over again. My truck has 130k on it and the oxygen sensors have never been replaced so I thought that was most likely the problem. Replaced the two primary sensors and the truck still idles horribly. I've been told all sorts of things: PCV, TPS, O2 sensors, bad cats, IAC, etc...
So I scanned the codes and came up with a PO161, which is some sort of malfunction in the downstream driver O2 sensor. While doing some inspecting around there, I noticed that the wires on the downstream passenger O2 sensor have worn through and are possibly grounding on the tranny mount. That one obviously needs to be relaced.
So I want to know if I can expect the truck to run fine after replacing the back O2 sensors. If not, what should be the next step I take?
#2
Well it's been a while since I've broken my truck, so it's good to see you all again.
About two weeks ago my truck started idling really rough. The RPMs drop to 500 then surge up to around 1100, then start over again. My truck has 130k on it and the oxygen sensors have never been replaced so I thought that was most likely the problem. Replaced the two primary sensors and the truck still idles horribly. I've been told all sorts of things: PCV, TPS, O2 sensors, bad cats, IAC, etc...
So I scanned the codes and came up with a PO161, which is some sort of malfunction in the downstream driver O2 sensor. While doing some inspecting around there, I noticed that the wires on the downstream passenger O2 sensor have worn through and are possibly grounding on the tranny mount. That one obviously needs to be relaced.
So I want to know if I can expect the truck to run fine after replacing the back O2 sensors. If not, what should be the next step I take?
About two weeks ago my truck started idling really rough. The RPMs drop to 500 then surge up to around 1100, then start over again. My truck has 130k on it and the oxygen sensors have never been replaced so I thought that was most likely the problem. Replaced the two primary sensors and the truck still idles horribly. I've been told all sorts of things: PCV, TPS, O2 sensors, bad cats, IAC, etc...
So I scanned the codes and came up with a PO161, which is some sort of malfunction in the downstream driver O2 sensor. While doing some inspecting around there, I noticed that the wires on the downstream passenger O2 sensor have worn through and are possibly grounding on the tranny mount. That one obviously needs to be relaced.
So I want to know if I can expect the truck to run fine after replacing the back O2 sensors. If not, what should be the next step I take?
#3
Disconnect the battery, fix the broken wire. Re connect the battery (it should have been disconnected for at least 15 minutes I'd think).
Start the truck, but DON'T touch the gas pedal or do anything, other then let it idle for a few minutes... It'll rise up and down some initially, but it's just adjusting itself and then it 'should' find it's idle and run fine....
Take it out and drive it around and then see if the code pops up again. The initial code could be just because of the broken wires??
Anyway, it's the computer and other sensors and hardware that control the idle, so start there first, then start trouble shooting...
At least, that's what I would do...
Mitch
Start the truck, but DON'T touch the gas pedal or do anything, other then let it idle for a few minutes... It'll rise up and down some initially, but it's just adjusting itself and then it 'should' find it's idle and run fine....
Take it out and drive it around and then see if the code pops up again. The initial code could be just because of the broken wires??
Anyway, it's the computer and other sensors and hardware that control the idle, so start there first, then start trouble shooting...
At least, that's what I would do...
Mitch
#4
I forgot to mention the auto parts store was nice enough to let me put in a new TPS in their parking lot to see if it would help. It didn't, so that's another thing ruled out. Assuming the weather holds up, I'm gonna go clean the MAF and try to repair the grounded wires in a bit.
Thanks for the help thus far and keep the replies coming.
Thanks for the help thus far and keep the replies coming.
#5