P1133, P1135 Rear A/f Sensor, Car Running Mostly Fine, Makes A Weird W

[pdxdrizzle]

Hi all, I need some help diagnosing check engine light.

So a couple weeks ago the check engine light came on, and I took it to autozone and the pulled codes P1133, and P1135.

P1135 is for the A/F sensor heater. P1133 is for the sensor itself and says it could be a Fuel Pump, injector, pressure regulator, a vac leak, or a fault sensor.

From everything I've read, it doesn't really seem like the A/F sensor is bad. The car doesn't run poorly at all except for an occasional pulsating idol. It also does a weird thing (maybe unrelated?) but when I'm accelerating up a hill, there's a weird squeaky whining noise that hits about about 2500 RPM and drops off shortly after or as soon as you let off the throttle.

My thinking is it's a vacuum leak, which is causing this weird noise. I've read a bit about how to check vac leaks, but I'm not sure where to look for the bank 1, sensor 1 A/F because it's tucked on the back of the engine.

Thanks in advance for any help. I'm trying to avoid having to go in to a mechanic if I can, and I don't want to just throw money at the problem if I can go about it intelligently. A/F sensors are expensive.

Thanks in advance for any help!

[lenore]

first of all welcome aboard....Here is a thread that might help you...I stress buy original equipment air/fuel sensor only, many have had problems with aftermarket. Denso only.....

http://www.clublexus.com/forums/rx-first-generation/340899-warning-lights.html

[pdxdrizzle]

Lenore,

Thanks for the reply! I have read a good dozen posts on how to replace the A/F sensor on these cars. But, what I am really curious about is ruling out a vacuum leak before I go buy a $200 sensor.

Like I said above, there is a strange noise that I think could be a vacuum leak, during driving at certain speeds. My gas mileage hasn't changed, and the only other symptom is a very occasional rough idol.

I looked around under the car near the A/F sensor, but was having a hard time finding the vac lines to trace and check. I just would like to know where the vacuum lines for this sensor are so I can see if a $10 hose will work before I buy a $200 sensor.

Thanks!

[lenore]

by the way the sensor can be had on Amazon for around $100.....