Need PT Cruiser help

My neighbor has an 03 PT Cruiser 2.4 non turbo. He has an oxygen sensor code P0031 so I replaced the upstream oxygen sensor (Bosch direct replacement four wire heated) but he is still getting the code. When he took it to get emissions tested the mechanic said it might the fuse to the heated wire. The stupid Haynes book does not even have a decent wiring diagram and I checked both fuse boxes and can't find an possible culprits. My net searches come up with generic crap so I am at a standstill. I am tying to help him out but this car is starting to piss me off.

Any ideas?

Steve

maybe its the secondary one? /obvious answer

In reply to Strizzo: Thought that but the code indicates the first. The other issue is that everyone sells the first as a direct replacement and the second as a generic that needs to be spliced in. I am going to let him drive it for a couple of days and see if it clears out. If not then I will tackle the downstream sensor.

what is the wording of the code exactly? heater circuit? slow response?

now wait, you did clear the code after the repair right?

In reply to belteshazzar: disconnected the battery and let it sit for an hour. Best I could do at the time. I know where you're going with this and I agree that it might be a code in memory but I am putting together my plan if it does not clear out. I can usually get the Autozone to clear codes for me but they are starting to get weird about doing it lately.

Code: P0031 HO2S Heater Circuit Low Voltage Bank 1 Sensor 1

Buy a harbor freight scan tool, auto zone has stopped doing anything but selling them (no returns) for like $200. I think they were pressured too much by the auto rapair places that charge $80 to read the code. Check the wiring too though, if I remember right my dads neon had a problem with that.

Travis_K wrote: Buy a harbor freight scan tool, auto zone has stopped doing anything but selling them (no returns) for like $200. I think they were pressured too much by the auto rapair places that charge $80 to read the code. Check the wiring too though, if I remember right my dads neon had a problem with that.

really? i just had a code read on my truck a couple weeks ago at the zone no problem.

edit: unhook the battery, and then turn on the headight switch for a couple minutes. then hook everything back up. this will for sure clear the ecu (and the radio)

Same deal on my '97 Volvo. I replaced the front O2 sensor but the code returned. Volvo forums indicated that vacuum hoses are also usually at fault. Sure 'nuf, found two that crumpled in my hand, replaced them, disconnected the battery for 10 minutes, reconnected and all has been well for over 1k miles.

So, check those hoses. Maybe some PT Cruiser forum can be more specific.

Strizzo wrote:

Travis_K wrote: Buy a harbor freight scan tool, auto zone has stopped doing anything but selling them (no returns) for like $200. I think they were pressured too much by the auto rapair places that charge $80 to read the code. Check the wiring too though, if I remember right my dads neon had a problem with that.

really? i just had a code read on my truck a couple weeks ago at the zone no problem. edit: unhook the battery, and then turn on the headight switch for a couple minutes. then hook everything back up. this will for sure clear the ecu (and the radio)

Yeah, at least here they on longer do it. It used to be you could "buy" (rent) one, and as long as you didnt use it in their parking lot, you could return it when you were done. Now, they no longer do that, you can only just buy a brand new one, and you cant return it.

wow i can walk into any of the advanced/zone/oriley places here and most of the time they'll point at it/hand it to me... other times they'll come out and read it for me.

sorry no help with the problem itself...

I do not know about chryslers, however Hondas hate the aftermarket bosch sensors. I was throwing a upstream o2 out of range code, replaced with bosch, still had the same code, replace with a non heated honda o2 sensor and the new code was for a bad o2 heater circuit, got the factory honda sensor (denso makes it) and no codes-problem solved.

As it said, " heater circuit low voltage". The 02 sensors get their voltage from the ECU.

bengro wrote: I do not know about chryslers, however Hondas hate the aftermarket bosch sensors. I was throwing a upstream o2 out of range code, replaced with bosch, still had the same code, replace with a non heated honda o2 sensor and the new code was for a bad o2 heater circuit, got the factory honda sensor (denso makes it) and no codes-problem solved.

Bingo. Put an OEM sensor in there and all is good now.