O2 sensors or cats

[ZGHOE05]

Thew a p0420 and p0430 code , just bought 4 new o2 sensors ,should i replace the sensors first and see if that helps or say to hell with it and drop 250 plus on the cats (ps i baught ac delco brand since ive had issues with non oe sensors in the past)

 

[treehan77]

well, you say you already bought them...

 

[ZGHOE05]

just waiting on the post man , amazon is an amazing tool

 

[PNWYukon]

From AllData: If the catalyst is functioning correctly, the HO2S bank 1 sensor 2 and HO2S bank 2 sensor 2 signals will be far less active than the signals that are produced by HO2S bank 1 sensor 1 and HO2S bank 2 sensor 1. This indicates that the TWC oxygen storage capacity is at an acceptable threshold. When the response time of the catalyst monitor sensors are close to that of the fuel control sensors, the ability of the catalyst to store oxygen may be below an acceptable threshold.

Get a FreezeFrame on a OBD and see those numbers. That should help determine if its the cats or not.

 

[ZGHOE05]

Did a temp test on the cat and only saw an increase of around 70 to 100 degrees ,i thought that was fairly normal. Then i took pictures of the live data on the o2 sensors

 

[PNWYukon]

Wow.

Here is some other data:

• The PCM determines that the oxygen storage capability of the TWC has degraded to less than a calibrated threshold.
• This diagnostic may conclude in only one test attempt. However this diagnostic may require as many as 18 test attempts, which would require 3 ignition cycles. Each test attempt occurs within 1.5 minutes .

• The catalyst test may abort due to a change in the engine load. Do not change the engine load, ensure the AC is OFF, the coolant fan is not cycling, while a catalyst test is in progress.
• Driving the vehicle under the conditions outlined in the Inspection/Maintenance (I/M) section can verify whether the fault is present.
• These conditions may cause a catalytic converter to degrade. Inspect for the following conditions:
• An engine misfire
• High engine oil or high coolant consumption
• Retarded spark timing
• A weak or poor spark
• A lean fuel mixture
• A rich fuel mixture
• A damaged oxygen sensor or wiring harness
• If an intermittent condition cannot be duplicated, the information included in Freeze Frame data can be useful in determining the vehicle operating conditions when the DTC was set.
• The catalyst may have been temporarily contaminated with a chemical from a fuel additive, fuel contamination, or any of the above conditions.

 

[ZGHOE05]

Well damn lol it could be anything then basically, not to sound like a dick . I did have a bad crankshaft position sensor prior to all this and it ran awful , knocking and barely running ,im thinking that extra fuel and horrible running conditions caused the cats to get contaminated, long story short it looks like im gonna see about changing them asap

 

[PNWYukon]

Well damn lol it could be anything then basically, not to sound like a dick . I did have a bad crankshaft position sensor prior to all this and it ran awful , knocking and barely running ,im thinking that extra fuel and horrible running conditions caused the cats to get contaminated, long story short it looks like im gonna see about changing them asap

Sounds like you got it.