lexusben

iTrader: (3)

So my Engine Light came on yesterday. My GS 400 is still riding perfectly, but I went to the shop today to get it checked out. The diagnosis was that I need to replace my O2 sensor which has failed. The man noted that if I did not replace this sensor ASAP, the Catalyst Converter could fail. To replace the O2 sensor would be around $500. I was just wondering whether this was reasonable or not?

werewolf

How old is the car? How many miles?

Is the o2 sensor before or after the catalyst? The post-cat sensors don't affect anything

A sensor runs $100-$150 online so it depends on how much labor is involved but 500 sound high and it sounds like a scare tactic. pass

FrankT

Did you get the OBD II code, you have 4 o2 sensors.

If you are comfortable changing your oil, you can replace the o2 sensor.
You need to know which one to replace though.

good luck

3UZFTE

That's pretty consistent with that it's like to lose an O2 sensor, you will need to figure out which sensor it is. I believe you need a 21mm O2 sensor socket, as most are 7/8"-22mm which is slightly too big. Autozone has a 21mm, and you can always make your own out of a deep 21mm socket. Hell you might not even need a special socket if your replacing the sensor, you might have to cut the wires off anyhow, just cut them off before you remove the sensor... Just make sure it's the right sensor before you do!!! A good way to check is to unplug the suspect sensor and see if the code stays or if another one appears, but obviously the best way is to have a scanner with someone who knows how to diagnose. The mechanic is right is saying that it COULD fail, but it's his job to say... If you don't replace your bald tires, they could eventually lead to a flat tire.. Same thing, what the O2 sensor does is that it tells the ECU how much oxygen is in the fuel mixture at any given time, as the ECU already knows the fuel distribution.
By not having a sensor that can read the info, the ECU is somewhat blind, and must go to preset perimeters to be able to run accordingly. This is what is know as open-loop, like when you start your car in the morning, it will run on preset programming to allow the engine to drive as you please. When the engine is being started it looks at it's engine coolant temp sensor and says you know 20* is a little cold for me, so I'll stay inside and let everything happen by itself. But when it hits 180*, the ECU think it's a nice day outside, and thinks hey, I might step out for a bit, and once the ECU hits that temp, it will start to wake up and see and read from oxygen sensors, air intake temp, coolant temp, etc, etc. to all weigh in on the given A/F mixture and start to adjust your fuel trim, which is a planned strategy that the computer uses to adjust for any variances in the system.... If it runs to rich it can burn out a cat in no time, if it runs to lean, it can also burn out a cat, either or aren't good, but it's not like within 100 miles you'll need to replace your cats... he's just guessing that if you don't do it within 6 months,it could happen. It's his job to say, your car needs service, so he's not going to say hey your good, who needs a cat anyways, **** I don't run with them, because he taking food off of his table when he does.....
Anyways! Rockauto.com has them listed from $50 for universal fit and $132 for direct fits. The difference being that one will plug right in, the other you will have to cut the plug off the old O2 sensor, and solder it on to the new sensor, hence universal, which is pretty easy and works perfect. Keep in mind that there is an upstream and down stream as well as a left bank and a right one, most of the time it is they are all the same sensors, however the wiring and connector is what will make the cost vary.

lexusben

iTrader: (3)

Thanks guys, I guess I will call the place back and see if I can get the code, then go from there.

BichoteGS

if you get a aftermarket 02 sensor it will most likely go bad after justa few months they are cheap. Denso is the best recommended for our cars and will last another 5-10 yrs. they are 200-300$ labor is 1.5 hrs to 2 depending on dealer thats why the price. if you dont know what your doing you could strip the thread and be even more costly. if you do attempt it yourself i recommend spraying "alot" of penetrant and letting it sit for a while. also check the code. most likely the code will be for 02 sensor heater circuit malfunction. that means the sensor is still good but the internal heater is bad. that will cause you to waist a lil more gas when the engine is cold but will run fine after the engine hits operating temp. i have codes for the heater circuit on all 4 of my sensors i fixed the light by removing the dash and unplugging the light for check engine lol. if it is a heater circuit code it is not to severe and will not damage anything

lexusben

iTrader: (3)

Okay so the Failed Sensor was Bank 1 Sensor 2 if that means anything to you guys.

3UZFTE

Ok, well Denso has a universal kit, so I guess that means their's will go bad within a few months, (no it won't). I have replaced a tons of O2 sensors with universals, doesn't really matter what brand you use, Bosch or Denso, they both are Ok to use. It really is a very easy task and can be done in less than 30 mins if your prepared. The heater circuit in the O2 sensor isn't for when the vehicle is cold, in fact it isn't even reading the O2 sensors until it hits operating temperature, which is over 600*, which is when it creates voltage, before 600*, it cannot create the voltage it needs to read the oxygen content. If the heater circuit on your O2 sensors are not working, your O2 sensors are not functioning correctly, thus not making it operate correctly until the O2 sensor reaches operating temperature. Your car is preprogrammed to run under preset conditions in order to be able to drive, this is known as open loop. As it heats up, it goes into closed loop, thus not requiring the heating of the O2 sensor... I am not sure that is the recommended fix that Lexus had in mind, nor would I think if you ran a business, that would be the proper way to fix a customer's car...so as far as advice goes, please don't tell him that it won't ruin anything by his car not properly, because it certainly will.

3UZFTE

Yes it does, the sensor code means that it is on the bank with the #1 piston, usually the driver's side. and the sensor #2 means that it's down stream, which is closer to the rear. So off the top of my head, it's your driver's side rear sensor.

macd7919

iTrader: (10)

$500 is ridiculous for that job. You can do it yourself or if you take it to someplace reasonable you should be looking about $100 for the sensor and 1 to 1.5 hours of labor, figuring an $85/hr labor rate you should be paying $250 at the most for the whole job with parts, and that is on the medium to high side.

lexusben

iTrader: (3)

Thanks for all the input guys, I appreciate it. I am going to get the code tomorrow, and I'll see where things go from there.

I should have came here before I began investigating the Engine Light Problem. It cost me a $100 inspection to have the problem diagnosed, an expense which could have been avoided if I just went to a parts store and had the code read out

FrankT

Or, for that price you could have bought a VERY nice OBD II code reader...

lexusben

iTrader: (3)

How can I determine whether it is the heater wire, or the actual sensor that has failed?

FrankT

By either checking resistance for each circuit or reading the codes.

An example of the 2 codes for Bank 1 Sensor 2.

P0141 Heated Oxygen Sensor Circuit - Bank 1 Sensor 2.
P1150 Air/Fuel Sensor Circuit Range/Performance. Bank 1 Sensor 2

lexusben

iTrader: (3)

Are there any DIY's for the Bank 1 Sensor 2 on the 400. I have seen other O2 DIY's but I can't seem to find one for the Bank 1 Sensor 2.