Is250 2007 Fuel Injection - Too Rich

[Tom Wingo]

My new IS250 '07 (awd) is running too rich according to the dealer. Every ~600 miles I end up with my 'check engine' light and numerous other warnings showing up on my dash. The O2 sensor has triggered the CE light and the dealership simply changes the oil and resets everything. I'm told that that it's a firmware/software bug causing the fuel mixture to be too rich and that a fix might be coming in Feb. I'm guessing my oil is getting dirty (or loaded with fuel) and that's causing the O2 sensors to trigger. All these oil changes are getting annoying.

Is anyone else having this problem? Given that it's a firmware problem I would expect other '07 models to be having this problem. I'm also amazed that it's going to take until Feb to fix the problem.

[RJM-07 250]

My new IS250 '07 (awd) is running too rich according to the dealer. Every ~600 miles I end up with my 'check engine' light and numerous other warnings showing up on my dash. ...

Is anyone else having this problem? Given that it's a firmware problem I would expect other '07 models to be having this problem. I'm also amazed that it's going to take until Feb to fix the problem.

Hi Tom

I also have an 07 250, but so far, no problems with the mixture or CE lights. However, have < 5000 miles.

Cheers,

RJM

[bartkat]

My new IS250 '07 (awd) is running too rich according to the dealer. Every ~600 miles I end up with my 'check engine' light and numerous other warnings showing up on my dash. The O2 sensor has triggered the CE light and the dealership simply changes the oil and resets everything. I'm told that that it's a firmware/software bug causing the fuel mixture to be too rich and that a fix might be coming in Feb. I'm guessing my oil is getting dirty (or loaded with fuel) and that's causing the O2 sensors to trigger. All these oil changes are getting annoying.

Is anyone else having this problem? Given that it's a firmware problem I would expect other '07 models to be having this problem. I'm also amazed that it's going to take until Feb to fix the problem.

I hadn't heard of this problem before, but it ought to be something they can resolve without that much trouble. I'd contract district service if the dealer isn't able to handle it. If it's firmware, then they ought to be able to change that out, even change the entire ECU if it's necessary.

[Tom Wingo]

My new IS250 '07 (awd) is running too rich according to the dealer. Every ~600 miles I end up with my 'check engine' light and numerous other warnings showing up on my dash. The O2 sensor has triggered the CE light and the dealership simply changes the oil and resets everything. I'm told that that it's a firmware/software bug causing the fuel mixture to be too rich and that a fix might be coming in Feb. I'm guessing my oil is getting dirty (or loaded with fuel) and that's causing the O2 sensors to trigger. All these oil changes are getting annoying.

Is anyone else having this problem? Given that it's a firmware problem I would expect other '07 models to be having this problem. I'm also amazed that it's going to take until Feb to fix the problem.

I hadn't heard of this problem before, but it ought to be something they can resolve without that much trouble. I'd contract district service if the dealer isn't able to handle it. If it's firmware, then they ought to be able to change that out, even change the entire ECU if it's necessary.

I've just passed 3000 miles and have had at least 3 oil changes. It's a software/firmware update that does not seem to exist in the US for some reason. I've been told to just keep getting my oil changed when the lights turn on and wait till Feb. The dealer "hopes" the fix will be shipped then. Not what I call a good solution at the moment.

[bartkat]

That's starting to sound like a lemon law case. It seems to me that if people can put aftermarket fuel managment systems on their cars, then certainly Lexus ought to be able to replace some parts. That is, unless all the systems in all the cars are bad, and I'd find that hard to believe.

[DaRacerz]

Ya, this is not good. I would think the Oxy Sensor is contanimated by now as well. I'm personally at the 2k mark and have had no CEL as of yet, but like some of you, car looks like it runs rich, exhaust pipe is utterly black like its running extremely rich. I'm starting to think this is a simply a fuel mapping mistake in the computer and not just a part gone bad. this problem is widespread in what seems to be in the colder climates, but not sure how many r affected.

[Tom Wingo]

I'm personally at the 2k mark and have had no CEL as of yet, but like some of you, car looks like it runs rich, exhaust pipe is utterly black like its running extremely rich. I'm starting to think this is a simply a fuel mapping mistake in the computer and not just a part gone bad. This problem is widespread in the colder climates, but not sure how many are affected.

Well I'm at 3000 miles and from what I can gather from the service manager they are having to change a lot of IS250's oil as the sensors trigger from the oil being dirty.

They had better have a fix by Feb. I'm getting tired of driving an hour each way just to get an oil change. And yes, the tailpipe is black. It's pretty obvious that as it gets cooler the problem gets much worse from what I've seen.