No codes, power loss

[jfoj]

Blackhawk.

Can you get me 2 Logs, I will be able to get an idea if the catalytic converters are a problem by looking at the Post Cat O2 sensor behavior. I may not be able to tell you they are clogged, but I can tell you I think they are not clogged.

This could save you money and your wife quite a bit of time. I am not buying that the converters are clogged and giving intermittent loss of power, it could but I would expect many other symptoms.

I need a 4 minute warm idle and a steady highway cruise (45-60 MPH range) Log.

Converter problems really do not come and go, if the monolith is clogged, then they tend to stay clogged.

Read the updated PDF attachment.

 

[Rocket Man]

My clogged cats were an aggravating problem that took quite awhile to fully present themselves. I had several codes over a couple months that pointed to MAF, TPS, multiple cylinder misfires, etc. I would replace a part or clean something, then clear the codes and as long as it wasn't driven hard it would be fine until I hammered the throttle again or was going over mountain passes. Towards the end, if I shut it off and it cooled down it would be fine for short trips but once it got hot it would start doing it again; that's when I suspected the cats. A shop checked them for me and one was 60% clogged, the other 40%.

 

[retiredsparky]

Knock sensors and intake manifold gaskets ought to be a maintenance item after a lot of miles. The sensors are in a bad place, especially if the vehicle is in a cold weather state. Slush and salt getting into any electrical connection is a problem. Intakes on these engines are known problem areas. (Not the problem in this case, but you would replace the intake gaskets when doing the knock sensors).