I just bought an 04 with 43,500mi on it ran fine for 5 weeks. At that point i got the check engine light and some engine break-up. Went to the dealer Had the code read and the O2 sensor for the code replaced. Less then a hundred miles later and the light came back on and needed a Catalytic converter.

Even after replacing both of said parts istill have some disturbing engine break_up. Not as bad now that the Cat has been replaced but enough that i'm being robbed of power and don't believe it to be safe to tow my trailer for vacation.

NO check engine light yet after cat replaced and code reset, but i havent made it to the one hundred mile mark yet any ideas on what may be my problem?

 

Could be anything... Is it in need of a tune-up. I could see the original owner skipping or skimping on the maintenance at 30k if he knew he was gonna unload it around 40k.

EGR would be due at about 40k, and I've seen 'em bog a truck down without popping a CEL. Also it's probably WAY overdue for a throttle body cleaning...

 

Hopefully it's that simple. I gues my next route is to pull the plugs and wires and clean the throttle body.

The timing is still dead on and if i lay into it, it jumps up and goes. I don't know. just don't wanna be stuck paying for this damn thing and it not run!