Hello All,

I have been reading your posts for about a month now however this will be my first post.

Got my IS about a month and half ago now and I love it. Last night however, out of the blue, my engine light, master emergency, and skid control lights come on along with the message "CHECK VSC" on the multi-info display.

Took it straight to the dealer this moring and after a 15 min. wait they inform me that the lights and message were triggered by an O2 sensor. Apparently the car is running lean.

They also mentioned that it was the first time they saw this message appear on this vehicle, so they are waiting to hear from Lexus as to whether there is another fix for this problem besides just changing the O2 sensor.

This is what was inputted on the invoice:

Report on cause of M.I.L./Engine light on
DTC 2195 - A/F ration sensor B1 / S1 - signal stuck lean
Cleared malfunction code - recommend to monitor condition
& report if code returns

Well needless to say, all the lights came back on soon after I left the dealer.

My question is, has anyone else experienced this problem? I also have a K&N cone filter in place of the stock air filter box -- could this be the problem, even though service tech says its not?

 

Service is usually the first to point fingers at things like CAI's. And to answer your question, yes, it's entirely possible that you're now flowing enough air through your filter that your ECU can't compensate with enough fuel, resulting in a lean condition.

Put the stock airbox back in and see what happens. It's no guarantee, but eliminating variables is the best place to start. The only other way to see what you AF ratio is would be to get the car to a dyno and watch the AFR's in real time.

 

My guess is bad oxygen sensor. The DTC says the signal is stuck lean, not that it is intermittantly lean.

 

That's the ironic part --- the service tech said it was NOT caused by the air filter.

I thought about putting the OEM air box back in but there's a small problem with that -- when I got the K&N cone filter I didn't want to wait to buy a replacement pipe for the OEM pipe that connects the air box to the throttle, so I cut the little piece of pipe coming from the airbox (where the MAF is attached) in order to attached the new cone filter.

Apparently a new airbox will run me $680 (CDN) plus taxes!!

The other factor to consider is that I had the cone filter on for atleast 2,000 km before the lights came on. Is it possible that it could take that long before the computer recognized that there was a problem, even though when I left the dealer the lights came on within 15 minutes of driving?

Before I get flamed for cutting the air box --- I was only looking for more of a growl from the engine, not for increased power.

Anybody have this issue arise after having repaced the intake with a complete kit?

 

Anything's possible. If the dealer isn't going to hassle you about the intake, count your blessings and just let them fix whatever they feel needs fixing and hope that does the trick.

 

No, I did the LMS intake and haven't had a service light yet...

 

Same here. No problems.

Check the tubing and make sure that everything is tight/secure. Sometimes, a loose tube can throw off the O2 sensor.

 

Well I'm still waiting to hear back from the dealer as to whether they will just be replacing the O2 sensor or if there is another "fix" that Lexus suggests. I'll keep you posted.

Those that have the intakes and reporting no service lights -- have you had them on for several thousand km / mi?

 

Why would the O2 sensor affect the VSC?

Reason I ask is when I took off the sensor on the intake box to take it out and install my Mtech bulbs for the low beams the Check VSC light came on after. I restarted the car 3 times and it went away. I thought it was just a coincidence that it came on and thought it was a glitch. But now it sounds like I caused it by removing the plug on the Intake box. Thank goodness it went away. *phew*

 

I've had my LMS on there for about 6000 miles now and everything is fine.

 

I hope my K&N Short Ram will be fine.

 

PinoyBruin:

K&N short ram?! Where did you find that? I looked on their website but it didn't appear that they had any yet for the IS .... know where I can see picutres of it?


I went back to the dealer today and apparently the ECU software was already the latest version, so they changed the O2 sensor. My wife has the car now .. ....but she's reporting no more lights on the dash