pewe

If anyone has replaced an O2 sensor on their GS300, did you strip the interior parts to get at the plug, or has anyone simply spliced the new sensor to the existing plug using the wires on the underside.
Some sensors seem to have no plug but come with connectors for doing it this way and I wondered if there is any reason not to use this method.

potatomon

Why are you replacing the sensor?

I think it will work, but I believe some o2 sensors may have stainless wires which i think you can't solder, and you shouldn't have to replace that sensor anyway all it's doing is monitoring the performance of the cat, unlike the upstream sensor it doesn't affect f/a ratio or the way a car behaves.

exhaust leaks where the intake mani bolts up to the exhaust will make the computer think the sensor is faulty or the cat is bad.

do this at your own risk. I doubt anyone here had experience with this.

pewe

Thanks potatomon
Just to clarify - I am buying a 2005 GS300 (good deal with very low miles). The dealer said that when he traded it in it had an error code indicating that Bank 1 Sensor 1 was or had been faulty.
He cleared the error and it has not re-appeared.
Just in case the error was not an uncleared message from a previous error and the sensor does prove to be faulty in due course I was looking at ways to replace it (if needed) and saw the amount of work involved in getting at the plug - so wondered about splicing the cable as an alternative.
However I don't know if this may cause a problem.

potatomon

Both sensor 1 is located in the engine bay on the exhaust manifolds and those are very important. They are responsible for ensuring the engine runs at stoichiometric 14.7:1 air fuel ratio constantly adjusting the fuel injectors spray pulse width(how long it stays open for)

Sensor 2 controls the performance of the primary cats and you need to pull a few interior bits to get to the pigtail. It's not that complicated. These are not critical to the operation of the vehicle. On a different note, a catalytic converter that is detereorating poses a threat to cylinder walls if bits of the catalyst get sucked into the engine, with the cat being in such close proximity.

The ecm will erase codes stored if the condition does not re-occur after 40 drive cycles. It will take some driving for it to pop-up again if erased. It's not like the crank/cam sensors which will light up a CEL after 10 seconds if your timing marks are off.

potatomon

2005 with low km and good price??
more like beat to crap and odometer reading changed.

Don't buy it without an inspection or else you might be creating a thread about poor fuel economy soon.

They are bound to find problems with that car and you can get your money back by haggling the price due to repairs needed

pewe

Thanks for the sensor info.
Perhaps the info I saw was incorrectly identifying sensor 2 as sensor 1 because it detailed the removal of the central console to get to the connector block.
From what you are saying, if it was sensor 1 the fault code referred to, and the problem re-occurs, than hopefully it will be easy enough to replace.

With regard to the car, it's unlikely that the odometer has been changed - if it has then somehow the seller has managed to change all the mileage figures on the DVLA MOT records back to 2008, and counterfeited all the service records and allied paperwork.
However some people will go to all sorts of effort to make just a small amount of extra profit.