2005 Nissan Altima. Intermittently crank but not catch, helps when I give it gas?

Starting about a month ago I noticed rough idling, engine knocking when I started it, and some acceleration issues. I let it go until I turned my key and it cranked, but didn’t catch. Seemed to help when I would give it gas when cranking, though if it had already failed to catch even that wouldn’t help until randomly, hours later, it would start …

Sent it to the shop, they found a catalytic converter code and they replaced plugs and coils ($400) and it was fine for about 3 days -no more rough idle and it didn’t need to press the throttle to catch- when the check engine light came back on with the following codes:

P0420 catalyst system efficiency below threshold
P1612 nats malfunction (security system)
U1001 invalid or missing data for primary ID
U 1000 Lost communication with ECM
P0462 Fuel level sensor circuit low input
P0463 fuel level sensor circuit high input

Today it failed to start on the first go around (crank but not catch) but started after I gave it gas. Still dealing with rough idle.

It seems to start fine without giving it gas if the engine is hot. Mechanic last week seemed to think it wasn’t fuel pump, thought that the plugs and coils was the issue and not catalytic converter, but who knows…

Any idea what this could be? I’m stumped.

Unfortunately mechanics are alot like going to the doctor sad but true let’s try this and that if this doesn’t work that can get expensive with the sensors unfortunately one failed system or sensor can cause 20 different codes to show up if you buy any electronic parts from parts stores they tell you if you hook it up you can’t return it the trick is not to put the bolts or nuts back in to hold it in place with your hand if possible if not just be real careful not to leave any tool marks on said parts having said all that your gas cap could be the culprit or an O2 sensor or even a clogged up catalytic converter converters can get stopped up and cause all sorts of problems

I hope this helps in some way

Also try getting the codes reset a now auto parts stores will tell you they are not allowed to reset codes and that is accurate bunch of BS but none the less see if they will let you use the scan tool your self if you are a regular it’s usually not an issue but if they don’t know you those things are expensive most of the time you can. Even get one of the people to walk you through how to do it this just covers there butt good luck

The person asked this question 8 months ago and never returned . Also I gave up on your long sentence before making it all the way through .
The post dates are on the right side even with the user name.