Can’t get 07 to pass smog. Help with codes

Tried everything tired of putting money into it runs great sometimes engine light is on. Sometimes not. I’m assuming the last thing is the cat. It’s been a mess

 

Why assume the last thing wrong is the cat? That's literally what the code is stating

When you're driving down the road the computer is watching the performance of the cat. Sometimes it works enough to pass the self test, sometimes it doesn't, that could be why the code comes and goes

Did a shop already replace that cat?
Has anybody checked for exhaust leaks?
How many miles on the truck?
Any history of misfires?
Any modifications done to the engine or exhaust?

On a stock vehicle if the long term fuel trims are stable and under 5% pos/neg while driving then the cat is likely bad

 

What work has been done to it?

 

250k no mods but def has mileage on it. We changed the sensors and that’s it so far still coding

 

We replaced the camshaft sensors and the brakes and the timing belt

 

Were O2 Sensors replaced too?

 

Replace dry rotted or cracked vacuum hoses. How many miles on the spark plugs?

 

We have not replaced O2 and spark plugs are new

 

Either troubleshoot it yourself or take it to someone who will

Troubleshooting is actually cheaper than throwing parts at it

 

Your scan tool doesn’t look to show live data of the A/F and O2 sensors.
It’s going to be tough for you to diag yourself.

The cam sensor would not have made a difference.

With 250k, I would guess the cat is bad.
But guessing, is just that, a guess.

 

Im betting its an electrical issue. Check resistance at your grounds. I recently went through hell and found a subpar audio install where the ecu ground on the passenger kick was completely in the wrong place and the anplifiers were grounded next to it.

Always check basics first. You shouldve spent that money on a proper diag software that would show you steps per fsm and not just parts cannon it