My check engine light came on ( P0430 ) Catalyst System Efficiency Below Threshold Bank 2 --- I am not convinced the cat needs replaced --- Need some suggestions ,,Thank you

 

Welcome to the forum. The reason you're "not convinced the cat needs replaced" is? Hang a scan tool and watch the bank 2 post-catalyst O2 sensor readings bounce back and forth by the same magnitude centered around 0.45V. If so, unless there's some sort of a rhythmic exhaust leak around that sensor (a highly unlikely scenario), the catalytic converter isn't doing its job.

 

99% of the time a converter code turns out to be a bad cat. Only use an OE replacement as most aftermarkets do not last long at all.

 

Thank you so much the reading are doing just as you described, The reason I didnt believe it is some times it will idle smooth and other times it is a little rough and I had someone say they think there is a sensor which will work some times and other times not so much so for the past week I have been pulling every sensor off and checking but not finding anything wrong , looking for vacuum leaks , checking plugs testing plug wires, Also I had a guy tell me if the cat was bad it would smell like rotten eggs and or rattle well I dont see or smell anything, But most of all the dealer wants 500+ for the Y pipe but I guess I will bite the bullet. Thank you so much for your response.

 

Thank you for your response I have looked and tested every sensor from the MAF to the post O/2 all checks good. so I guess all that is left is to go to the dealer and ask for a credit application. again thank you.

 

Rattling would only occur if the innards of the converter actually were broken, I think the smell is when the converter IS doing its job but in overtime...
The converter is most likely blocked due to a poorly tuned engine, lots of miles or poor fuel quality...