LS400_96

Hi,

I am getting a check engine light for my lex. I got codes DTC 420 and 430 on different occasions (Catalyst System Effieciency Below Threshold -- Bank 1 and Bank 2 respestively). In the service manual it says problem is either 3-way cat or O2 sensor. WIth all the problems with O2 sensors here in the forum, I too am thinking my sensors are bad. I have about 125,000 miles on my car and I dont think the previous owner ever changed it (checked and looks original).

I checked prices with Steve at Carson Toyota and he wants like $110 for each sensor. I think this price is ridiculous for some sensors. I am trying to get some aftermarket sensors. I heard of alot of people getting Bosch ones. I checked Autozone and they have them for $70, and I also found some made by Denso from oxygen-sensors.com (http://www.pickproparts.com/PartsLis...ategoryID=5132) for around $50 (part number 234-4209 for Universal and 234-4169 for OE type). Are these sensors the same as the ones from Toyota? I know that they use alot of parts from NipponDenso.

Also, I think sensors on both banks are bad since I am getting codes from both banks. I am not sure if the front or rear ones are bad. Does anyone know how to check which ones are bad? I know you can check it with a scope but I do not have access to one right now. Is there any other way I could check this?

LexLS

Here's another place that sells aftermarket sensors cheap: http://buyoxygensensors.com
I think the main difference between the toyota ones and aftermarket ones is that you have to splice the wires on the aftermarket ones. Not a big deal when you're saving $50-$60 per sensor!

I have about 133,00 miles on my LS now, but no warning lights. Just for maintenance I'm going to change all four oxygen sensors sometime soon. The site I mentioned above has some good info about how to tell if a sensor need replacement.

VVT-i

I've seen a lot of 95-96 LS with these codes and most likely the catalyst converter is bad.