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?

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?

additude

Hey,

I just had this problem.

Little did I know before I spent $660 on 4 new O2 sensors that the cats were so plugged up they were burning up the O2 sensors. I had called and was told the O2's were not covered under warranty.

I replaced the sensors and still had the problem and had to take it in for service.

But life will be life.

My ride was still under warranty so they replaced the cats and had to put new O2 sensors in because the cats were causing the O2's to go bad.

I looked at aftermarket parts, but that was a lot of work, cut and splice the wiring, etc.

If I was you I'd start with O2's, but be prepared for the worst. If your complaining about the price of O2's, get prepared to really bit*h when you see the price of 2 new cats plus labor.

My service bill came to $2,076...but it was under warranty. Whew....