P0420 after New cat, help please. - Toyota Yaris Forums

ncp13 · 01-23-2017, 07:22 AM

Hello

As per the repair manual

DTC P0420 is detected when the vehicle is driven at an average vehicle speed of approximately 50 km/h (31 mph) with a city driving pattern for approximately 30 minutes, and then driven for approximately 15 minutes at a constant vehicle speed of between 70 km/h and 90 km/h (43 mph and 56 mph) with the transmission gear selector lever in the 5th position. (If the engine speed remains 1900 to 3400 rpm and the engine load remains 25 to 50 % after the catalyst is warmed up for 60 seconds or more, the detection for DTC P0420 will be performed)

I havent seen a bad (new) cat but check for a bad (new) sensor B1S1 and B1S2. Pins ok in the plugs ? Maybe loose?

I can post the proccedure if you want but you will a Toyota THS2 or similar to increase or decrease injection volume so you can check the response from the sensors .

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01-23-2017, 07:22 AM	#7
ncp13 Drives: 01 Yaris TS Join Date: Jan 2017 Location: Athens Greece Posts: 92	Hello As per the repair manual DTC P0420 is detected when the vehicle is driven at an average vehicle speed of approximately 50 km/h (31 mph) with a city driving pattern for approximately 30 minutes, and then driven for approximately 15 minutes at a constant vehicle speed of between 70 km/h and 90 km/h (43 mph and 56 mph) with the transmission gear selector lever in the 5th position. (If the engine speed remains 1900 to 3400 rpm and the engine load remains 25 to 50 % after the catalyst is warmed up for 60 seconds or more, the detection for DTC P0420 will be performed) I havent seen a bad (new) cat but check for a bad (new) sensor B1S1 and B1S2. Pins ok in the plugs ? Maybe loose? I can post the proccedure if you want but you will a Toyota THS2 or similar to increase or decrease injection volume so you can check the response from the sensors .