P0330 & P0420 Appear after O2 sensors replaced (RX300)
02-06-15, 06:53 AM
#1
Driver School Candidate
Thread Starter
Join Date: Feb 2015
Location: Ireland
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
P0330 & P0420 Appear after O2 sensors replaced (RX300)
Sincere thanks to everyone that contributes to the forum section. This is my first post but just viewing previous discussions have helped me fix numerous problems. My latest problem is since I have changed out both front O2 sensors on my first Gen RX300 I am now getting new codes: P0330 (Knock Sensor 2 Circuit Bank 2) and P0420 (Catalyst System Efficiency Below Threshold Bank 1).
These codes only appeared once I had changed out the sensors after getting P1135 & P1155.
These heater codes have not reappeared since the sensors were replaced but only 3 days after successful fitting, CEL and VSC popped up again with the new codes!
Ideally I would have ordered 234-9009 heaters but I am in Ireland and European denso part #s are different and I simply couldnt wait for shipping from US. On the advice of my mechanic I replaced the o2 sensors with Denso Lambda (DOX 0242) Could the wrong sensor be the problem as these new codes were not showing up before the change? Any advice on the cause of the new codes and why they wernt showing up before or how to fix the problem would be greatly appreciated.
These codes only appeared once I had changed out the sensors after getting P1135 & P1155.
These heater codes have not reappeared since the sensors were replaced but only 3 days after successful fitting, CEL and VSC popped up again with the new codes!
Ideally I would have ordered 234-9009 heaters but I am in Ireland and European denso part #s are different and I simply couldnt wait for shipping from US. On the advice of my mechanic I replaced the o2 sensors with Denso Lambda (DOX 0242) Could the wrong sensor be the problem as these new codes were not showing up before the change? Any advice on the cause of the new codes and why they wernt showing up before or how to fix the problem would be greatly appreciated.
02-06-15, 05:19 PM
#2
Sincere thanks to everyone that contributes to the forum section. This is my first post but just viewing previous discussions have helped me fix numerous problems. My latest problem is since I have changed out both front O2 sensors on my first Gen RX300 I am now getting new codes: P0330 (Knock Sensor 2 Circuit Bank 2) and P0420 (Catalyst System Efficiency Below Threshold Bank 1).
These codes only appeared once I had changed out the sensors after getting P1135 & P1155.
These heater codes have not reappeared since the sensors were replaced but only 3 days after successful fitting, CEL and VSC popped up again with the new codes! Ideally I would have ordered 234-9009 heaters but I am in Ireland and European denso part #s are different and I simply couldnt wait for shipping from US. On the advice of my mechanic I replaced the o2 sensors with Denso Lambda (DOX 0242) Could the wrong sensor be the problem as these new codes were not showing up before the change? Any advice on the cause of the new codes and why they wernt showing up before or how to fix the problem would be greatly appreciated.
These codes only appeared once I had changed out the sensors after getting P1135 & P1155.
These heater codes have not reappeared since the sensors were replaced but only 3 days after successful fitting, CEL and VSC popped up again with the new codes!
Ideally I would have ordered 234-9009 heaters but I am in Ireland and European denso part #s are different and I simply couldnt wait for shipping from US. On the advice of my mechanic I replaced the o2 sensors with Denso Lambda (DOX 0242) Could the wrong sensor be the problem as these new codes were not showing up before the change? Any advice on the cause of the new codes and why they wernt showing up before or how to fix the problem would be greatly appreciated.
02-07-15, 10:36 AM
#3
Driver School Candidate
Thread Starter
Join Date: Feb 2015
Location: Ireland
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
Cheers for the reply. Yea I've read a lot on here about the picky they can be about sensors but since the old codes (P1135&P1155) are not appearing any longer It is hard to justify paying for another two A/F sensors. Surely the EMS would show these codes also if the sensors were responsible for these new codes?
02-07-15, 02:35 PM
#4
Lexus Test Driver
Welcome to Club Lexus!
It's possible. If the numbers from the 02 sensors aren't being communicated/read properly by the ECU, then the 02 sensor after the CAT will be trying to compare "false" numbers. Thus, you get a catalytic inefficiency code.
That's just a theory, not saying it's possible or impossible. Just something to think about.
Is there something that you referenced to decide which 02 sensor to install? Did you mechanic cross reference it, or just decide that since it fits it'll do the job?
It's possible. If the numbers from the 02 sensors aren't being communicated/read properly by the ECU, then the 02 sensor after the CAT will be trying to compare "false" numbers. Thus, you get a catalytic inefficiency code.
That's just a theory, not saying it's possible or impossible. Just something to think about.
Is there something that you referenced to decide which 02 sensor to install? Did you mechanic cross reference it, or just decide that since it fits it'll do the job?
02-11-15, 08:31 AM
#5
Driver School Candidate
Thread Starter
Join Date: Feb 2015
Location: Ireland
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
Welcome to Club Lexus!
It's possible. If the numbers from the 02 sensors aren't being communicated/read properly by the ECU, then the 02 sensor after the CAT will be trying to compare "false" numbers. Thus, you get a catalytic inefficiency code.
That's just a theory, not saying it's possible or impossible. Just something to think about.
Is there something that you referenced to decide which 02 sensor to install? Did you mechanic cross reference it, or just decide that since it fits it'll do the job?
It's possible. If the numbers from the 02 sensors aren't being communicated/read properly by the ECU, then the 02 sensor after the CAT will be trying to compare "false" numbers. Thus, you get a catalytic inefficiency code.
That's just a theory, not saying it's possible or impossible. Just something to think about.
Is there something that you referenced to decide which 02 sensor to install? Did you mechanic cross reference it, or just decide that since it fits it'll do the job?
Bit of an update on the problem. Started the car this morning and the CEL and VSC were no longer showing up until I drove for around an hour but have stayed on since. Ran the diagnostic and the new codes are showing again so perhaps it could be an intermittent Knock Sensor malfunction which is only throwing the code once the car has warmed up (saw this explanation on this site previously)? And I know I'm clutching at straws but couldn't the Catalyst System Efficiency code its throwing be a result of the knock sensor malfunction?
02-11-15, 11:01 AM
#6
A quick search with Denso Lambda (DOX 0242) the compatible toyota O2 sensor part number are: 8946728030, 8946733020, 8946733040, 8946742010, 8946744010, 8946744030.
The toyota RX300 part number is 8946748011.
You can try the old school way using a spark plug fouler as an adapter on the O2 sensor.
The toyota RX300 part number is 8946748011.
You can try the old school way using a spark plug fouler as an adapter on the O2 sensor.
Thread
Thread Starter
Forum
Replies
Last Post
daniel5xfl
RX - 1st Gen (1999-2003)
8
03-27-18 06:44 AM
4play4dr
GS - 2nd Gen (1998-2005)
14
06-12-13 05:20 PM
