What are the problems when it had diganostic codes of po 496 po 455 po442 and po121

Failed Ignition Coils

Resulting cylinder misfires over time
have ruined the exhaust converters (PO420 Bank #1)

PO442-small leak in Evap System

It's all on the internet ,if you Google your codes
& study OBD2 Systems

Type: OBD PO 442

On a 2005 vehicle-- All-- the ignition coils will be bad after
7 or 8 years

At 100,000 miles the front Oxygen Sensors need to be replaced

code p0121 refers to throttle position (TP)switch A/ pedal position (AAP) switch A-range/performance problem===causes --accelerator cable adjustment--TP/APP switch
PO121 also refers to TP sensor A/ accelerator pedal position AAP switch A -range / performance problem===causes --accelerator cable adjustment. TP/AAP sensor --wiring
Cheapest first is to check the cable adjustment then the cheapest part after that .

P0121 Throttle/Pedal Position Sensor/Switch A Circuit Range/Performance Problem
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car ecu repair tool

EVAP System ---PO 442 (small leak)

I'm going to guess, that will mean nothing to you

You need to have the vehicles EVAP System checked
out by a repair shop, that does know something,of your
lucky & get the right place.

PO 301 is no 1 cylinder misfire, PO 410 is secondary air injection system, & PO 442 is Medium leak detected in EVAP system.

PO121 is a throttle position sensor problem. I would be checking that if it stalls when you come to a stop sign and stuff like that.

PO-442 EVAP Control System Leak Detected (Small Leak)

You will need to put an EVAP Smoke Machine, on system to find leak

P1407--Should be EGR related.

Most likely need new EGR Valve

Hello! Those three codes commonly indicate the followi possibilities:

The gas cap was not sufficiently tightenend ater fueling, a bad gas-cap rubber o-ring, the vehicle had the key in the 'on', or engine running, or the tank was filed all of the way up the neck.

Any one of the abope causes will set all three codes.

Usually the source of the leak is the gas cap (either loose or defective) but if that doesn't apply to your issue then the canister is next to the gas tank.

PO442= EVAP system, small leak detected