I have four fault codes coming up and was wondering if any would trigger the others or if there was a certain order I should tackle these in.

My codes are as follows:
P1259 - VTEC System Malfunction
P0420 - Catalyst System Efficiency Below Threshold (Bank 1)
P0401 - Exhaust Gas Recirculation Flow Insufficient Detected
P1457 - EVAP Emission Control System Leak Detected (Control Canister System)

Now, I know I'm burning oil faster than I should be. I'm usually low by 2800 miles into a change so I'm uncertain if that would be caused by the VTEC or if the constant low oil keeps tripping it. I'm leaning more towards piston rings because of the rate of oil consumption.

I have not had the car on a smoker yet, but I'm guessing the combination of the P0420 and P0401 means I'll be replacing a decent chunk of the exhaust.

The Valve most likely needs to be replaced, but again it's freezing outside and I'm not checking right now .

I'm thinking the rings would be the first thing to tackle which might deal with the P0420 (hopefully, but probably not). Then moving on to the P0401 and saving the P1457 for last.

Any differences of opinion or other methodological ideas?

 

Year and model?

Burning oil could and would clog the EGR and engine passages (P0401) and ruin the catalytic convertor (P0420). Fix whatever is making you burn oil, clean the EGR and passages and replace the cat and sensors.

P1259 could be low oil or a bad VTEC solenoid or bad electrical connection/wire.

P1457 will be a bad valve around the gas tank or the charcoal canister itself.

 

If the EGR ports are clogged this would cause P0401 which in turn would cause inefficiency in catalyst function and set the P0420.
If a '96/'97 you will need to clean the EGR manifold on the intake, there is a write up in the FAQ at the top of the page. '98-'02 F23 cars will require the upper plenum to be removed and clean the inside passages. This will require a gasket kit for the upper plenum which is ~$5.

VTEC solenoid may be as simple as low oil condition, if you top off your oil and VTEC does work(engine revs smoothly up to redline) then it is just a lingering code from the low oil issue. If full oil and VTEC does not work, check the pressure switch at the VTEC solenoids base. It will most likely be a green connector.

P1457 may be a damaged or loose hose in the EVAP system underhood. P1456 would be related to the gas tank EVAP part of the system.

 

I knew I forgot something it's a 98 Accord LX V4 manual trans.