Hello all,

I've been reading alot from you guys on the code 420 for my 02 bonneville.... My code reader reads

420 bank 1...And I notice occasionally when I drive after awhile it will just start jumping or hesitating some and if you maintain your speed it stops but if you try to accelerate it does it more...and then eventually stops...I guess I'm looking for more insite, I've had one mechanic tell me its the cat prob clogged and one guy over the phone tell me I need this expensive test... And what is the bank 1 referring too...

Any help would be greatly appreciated...thanks

Take a look here and see if that helps. https://www.gmforum.com/t284086/#post1390979