2000 Rx300 Check Engine Light Multiple Codes

lexus808 · February 26, 2009

We purchased our 2000 rx300 2 weeks ago with 65K miles. Four days after owning it on my way to work the check engine light came on. I left for work in 50 degree weather and drove downhill (1800 ft elev drop) in 2nd gear for approximately 15 mins before the light came on while I was in drive on flat road. We took it into the dealer who pulled the code for the knock sesnor PO325. They charged $820 to replace the sensor. We picked it up on Friday and drove it all weekend with no problem. Monday morning on my way to work, again starting in cold weather (cold for Hawaii), the CEL came on again within 100 yards of where it did the first time. Very upset we took it back to the dealer who agreed to do the diagnostics free of charge. This time they pulled up 2 codes, the second knock sensor P0330 and the Air Fuel Ratio P1130.

Having a hard time believing that 3 sensors would fail at the same time, we asked to have the codes cleared and took the car back to do some experiments. We mainly wanted to make sure that the same codes would appear again before spending another $1100 on replacing sensors without looking for the root of the problem. I drove it again to work this morning in the same conditions and no CEL.

Other car history is that it is originally from Alaska and travelled the sea to Hawaii in 2005. Since then it has been living in a garage (in warm weather) for the most part, being driven a few times a year. So, we are wondering if these sensor readings could be triggered by the change in climate or the fact that car is not used to being driven as much. We did check with the dealer to make sure that the previous owner hadn't had similar issues and they had nothing on record besides regular service.

Anyone have any ideas? We are looking for something other than the dealer just saying the computer reads these codes so the sensors need to be replaced. Seems like there could be something else going on. Thanks.

lenore · February 26, 2009

The P0325 is a knocks sensor, but what grade Gasoline do you use? The wiriing harness to the knocks sensors also could be deteriated. But I would think they would have noticed that. Maybe the sensor harness plug has some corrosion in it. Unplugging and cleaning with contact cleaner would be good. As for the Air/fuel sensor. they go bad, but as for the computer, I doubt it....

lexus808 · February 26, 2009

We use 92 octane, premium. We can accept Air/Fuel sensor going bad, but it is the two knock that we can't believe. Thanks for the thoughts on the harness. We'll see what happens on the way to work this morning.

The P0325 is a knocks sensor, but what grade Gasoline do you use? The wiriing harness to the knocks sensors also could be deteriated. But I would think they would have noticed that. Maybe the sensor harness plug has some corrosion in it. Unplugging and cleaning with contact cleaner would be good. As for the Air/fuel sensor. they go bad, but as for the computer, I doubt it....

lenore · February 26, 2009

it may have been the air/fuel sensors causing the engine to not run right and then causing the engine knock sensors to come to surface....Funny everyone says if you are in there to replace sensor (knocks) replace both because the labor of getting in there....

lexus808 · February 26, 2009

Yep, my husband asked if it would be a good idea to replace both when the first code came up, but they said no unless both codes were coming up. My inclination at this point is to just replace the air/fuel sensor.

it may have been the air/fuel sensors causing the engine to not run right and then causing the engine knock sensors to come to surface....Funny everyone says if you are in there to replace sensor (knocks) replace both because the labor of getting in there....