'01 Rx300 Cel/vsc/trac Lights (o2 Sensor? Fuel Cap? Loose Hose Und

[darryl zero]

I'm taking care of my aunt's 2001 RX300, 160K miles on the clock. She reports that every now and then the check engine lights (and VSC, and traction control) go on, but then switch off after a few days. I've been driving thecar for the last week and three of those days the check engine lights were on. I took the car to a shop and the repoted it was a bad O2 sensor (bank 2, sensor 1).

I had an O2 sensor go bad in my '99 RAV4 and the MPG went to crap. Maybe 60% the fuel economy of the car normally. The RX300 is still pulling the same MPG with the light on as off... ~21 MPG combined city/hwy driving.

I've heard that the problem could be caused by a bad gas cap seal, or the hose under the airfilter box being yanked off. But would these cause the code reader to indicate that it was a bad O2 sensor? I don't want to spend $260 to replace the O2 sensor if it doesn't need it.

If it is the fuel cap, should I get a new one from the Toyota dealer or will a generic one from Pep Boys do?

If it is the hose on the air filter box, can anyone be specific as to the location of the hose? Can't tell if it's loose if I'm looking in the wrong place.

Thanks!

[PK_3]

Your wise not to rush into anything if it’s running well. There’s a “how to” somewhere here for the o2 sensor (I need one too).

$260? If that’s installed it might be worth it. It’s a big job. If it’s for the sensor only, shop around. My Porsche O2 sensors are about $50. That’s a Camery motor at its heart.

Regards, PK

[smyrnagc]

I had the very same problem with our 2002 RX 300...Trac/CEL/VSC and I had the codes read at Advance Auto. After researching the codes, mainly on this forum, I checked and sure enough the hose that is directly under the air filter box was off. The guy at Advance Auto recommended replacing the gas cap because this could cause that problem also....basically running lean. I bought the generic cap that was for our model Lexus ($9.00) and put the hose back on and made sure that it was secure. Had the codes cleared and the problem never came back.

That is not to say that it might be an O2 sensor but my research indicated that the Trac Off/CEL will come on for many other reasons other than O2 sensors. The air filter hose is sort of hard to see but it is directly under the air filter box on our model. I had also read that the Mass Air Flow sensor can get dirty and cause this problem so I bought a can of MAF cleaner at Advance Auto and cleaned it...might have also helped.

http://townhall-talk.edmunds.com/direct/view/.f19f657

http://us.lexusownersclub.com/forums/index...amp;hl=smyrnagc

Good luck and keepus posted

[darryl zero]

Your wise not to rush into anything if it’s running well. There’s a “how to” somewhere here for the o2 sensor (I need one too).

$260? If that’s installed it might be worth it. It’s a big job. If it’s for the sensor only, shop around. My Porsche O2 sensors are about $50. That’s a Camery motor at its heart.

Regards, PK

Yeah, the shop I go to (A-1 Auto in West Los Angeles) quoted $260 installed... $200 for the sensor (has to be California compliant) and $60 for labor. I was going to do my own rear suspension but the price they quoted me for two new struts installed was only $150 more than what it would have cost me for the parts and shipping, so I spent the cash to avoid half a day busting my knuckles.

Still, no need to replace an O2 sensor if it's the gas cap or an air hose.

If anyone can be more specific about the location of the hose which may have popped off, I'd appreciate it.

[smyrnagc]

On our 02 RX 300 it is basically directly under the bottom of the air filter box. You have to look and/or feel under the box to find it.

[Paticake]

Hi Darryl,

I had the same thing happen CEL/VSC lights and mine was because of the hose off of the air filter was disconnected.(I have an 02 RX300).

When you pop the hood, look right toward the side mirror and then down behind the air filter box. You should see a rubber hose. That should be placed over a metal tube. If it's already connected then you have to go to plan B.

Did you get the codes read and what are they?