Check Engine Light On Es300

[motoqman]

Two days ago, the check engine light of my 03 ES300 has been on. Many threads on this issue in this forum suggest to go to AutoZone to get the error code. I did that this morning. The error code is p2238. I was told that the issue is with bad O2 sensor. The replacement part costs $326 :cries:

Should I take to dealer or shop? Is there anything else I could do before like checking a loose wire?

Thanks in advance.

Ittichai

[steviej]

Two days ago, the check engine light of my 03 ES300 has been on. Many threads on this issue in this forum suggest to go to AutoZone to get the error code. I did that this morning. The error code is p2238. I was told that the issue is with bad O2 sensor. The replacement part costs $326 :cries:

Should I take to dealer or shop? Is there anything else I could do before like checking a loose wire?

Thanks in advance.

Ittichai

how many miles on the car? It may be covered under the 4year/50,000 mile warranty.

If not, which AF/O2 sensor is it, did they tell you? Should be (Bank 1 or 2) and then (Sensor 1 or 2). Of the four (2 AF and 2 O2), three are easy to get at with a cool engine and the sensors can be had at any Toyota dealer for about $225 (little more at Lexus) or online for about the same.

steviej

[motoqman]

how many miles on the car? It may be covered under the 4year/50,000 mile warranty.

If not, which AF/O2 sensor is it, did they tell you? Should be (Bank 1 or 2) and then (Sensor 1 or 2). Of the four (2 AF and 2 O2), three are easy to get at with a cool engine and the sensors can be had at any Toyota dealer for about $225 (little more at Lexus) or online for about the same.

steviej

It has only 33K. It is good to know that it is still under warranty.

I recalled it said Bank 1 Sensor 1. Anyway, last night I looked under the hood. There is only one sensor easily accessible without any tool. So I kinda checked for any loose wire. Everything seems to be in tact. Amazingly, when I restarted car, the light disappeared :o. I have been driving it for some more that night and this morning. It seems everything is fine (no more check engine light).

Is this possible that it is a false alarm - has anyone seen something like this before? Should I be concerned? Since it is still under warranty, should I bring the car to dealer and have them checked?

Thanks in advance.

Ittichai

[steviej]

It has only 33K. It is good to know that it is still under warranty.

I recalled it said Bank 1 Sensor 1. Anyway, last night I looked under the hood. There is only one sensor easily accessible without any tool. So I kinda checked for any loose wire. Everything seems to be in tact. Amazingly, when I restarted car, the light disappeared :o. I have been driving it for some more that night and this morning. It seems everything is fine (no more check engine light).

Is this possible that it is a false alarm - has anyone seen something like this before? Should I be concerned? Since it is still under warranty, should I bring the car to dealer and have them checked?

It may be just a sensor going faulty. Take it in to the dealer since it is under warranty. The code will still be in memory, they can test the sensor itself. If it appears "lazy", they will replace it under warranty. It is not uncommon to have this sensor go. Toyo/Lexus had a rash of AF and O2 sensors around 02-04 that were not the best made. They seemed to go prematurely. I had that same sensor go at 39,000 miles. Bank 1 Sensor 1 is the hardest of all go get at, too.

steviej

[motoqman]

steviej,

BIG thanks for your helpful information and suggestion. I'll take the car to dealer then.

Ittichai

[blk_on_blk]

I've had that happen before. There is a sinusoidal timeout in the ECU. What that means is there is a certain time alotted by the engine's computer to let the O2 sensor stabilize and give it's reading. If the sensor is slow to respond, it trips the 'check engine' light. On a sensor that is getting 'worn' and going out, this will happen sporadically. Sometimes it reads in the time alotted, other times it won't. You shouldn't have any problems in the meantime, but you should notice a couple mile increase in fuel efficiency when you get a new O2 sensor in there... plus the check engine light won't come on any more.

You can save some $$ on the sensor by getting a universal one with out the factory plug on it, if you are sure you know it will fit. Then you can just tin on your factory plug. Don't know if it's worth it... I'd have to see the price difference if applicable.