Cel Code P0430

[tofu]

My 01 IS300 CEL came on couple of weeks ago code P0430 Catalyst Eff. below threshold Bank 2.

We thought it was the Catalytic so replaced it but after 300 miles or so same code came back on.

Any help will be appreciated. Thanx.

[smooth1]

02 sensor needs to be replaced. Make sure you get the Denso's and not Bosch. They aren't to hard to replace. Costs around 60 bucks. Alot more if you have a tech do it for you.

[tofu]

02 sensor needs to be replaced. Make sure you get the Denso's and not Bosch. They aren't to hard to replace. Costs around 60 bucks. Alot more if you have a tech do it for you.

Please tell me which one is 02 sensor. Thank you for all the help.

[curiousB]

02 sensor needs to be replaced. Make sure you get the Denso's and not Bosch. They aren't to hard to replace. Costs around 60 bucks. Alot more if you have a tech do it for you.

Please tell me which one is 02 sensor. Thank you for all the help.

Check for leak in pipe before or after secondary O2 sensor. I had that problem on LS430 and changed parts befoe I got the right answer. Welded pipe leaks shut and all is well.

[tinh_x7]

(I can't find the option to insert attachment.)

According to Alldata v10.40:

2001 Lexus IS 300 L6-3.0L (2JZ-GE) Copyright © 2011, ALLDATA 10.40 Page 1
Oxygen Sensor: Technical Service Bulletins
Engine Controls - Bank 1/Bank 2 O2 Sensor Identification
ENGINE
EG015-07
Title:
ENGINE BANK 1 AND BANK 2 A/F AND
02 IDENTIFICATION
Models:
'90 -'08 Applicable Models
June 28, 2007
TSIB UPDATE NOTICE:
The information contained in this TSIB supercedes TSIB No. EG010-04. TSIB No. EG010-04 is now obsolete and should be discarded.
Introduction
This service bulletin provides information on the proper identification of engine bank 1 and engine bank 2 for correct A/F sensor and oxygen sensor
replacement.
This bulletin contains information that identifies engine bank 1 and engine bank 2 on the following engines: 2GR-FE, 2GR-FSE, 4GR-FSE, 2JZ-GE,
1MZ-FE, 3MZ-FE, 1UR-FSE, 3UR-FE, 1UZ-FE, 2UZ-FE, and 3UZ-FE.
^ Bank 1 (B1) refers to the bank that includes cylinder No. 1.
^ Bank 2 (B2) refers to the bank opposite bank 1.
^ Sensor 1 (S1) refers to the sensor that is located before the catalytic converters.
^ Sensor 2 (S2) refers to the sensor that is located after the catalytic converters.

[IanH]

This is the one under the drivers seat, and I had the same issue. Since i had 140K and just replaced the clutch, so gaskets were new, I didn't believe it was anything to do with leaks.

Replacing the CAT with new Y pipe under the floor seems excessive on a 8yr old car, so I used an O2 cheater for $15- 20

Anyway I agree with above

1) check for leaks and gaskets

2) replace O2 Sensor

3) replace CAT or O2 cheater