Code p0460 on 2000 accent and code p1124 - 2000 Hyundai Accent

Install the new Oxygen Sensors

Google the P1124 & read up

Type: Ford OBD P1124

code p1124 refers to long term fuel trim--additive-mixture too lean===causes --HO2s---fuel pressure--fuel system---mechanical fault---ECM

You use Google to look up any OBD2 Codes

You got issues that are beyond the home driveway,
you need a repair shop

You have serious rich condition, that most likely has ruined
the exhaust converter by now & washed the engine cylinders
of oil & contaminated the oil with fuel

Misfires along with the leaking injectors,vacuum leaks &
all,it's a mess,lots to diagnose & work on

The codes is for a tps sensor,that isn't going to fix much
of what you got going on

The battery & charging system have issues you can't
figure out

I would leave it at a shop for a week or more

The 300 codes are for engine miss, 300 is random, 302 is cylinder number 2, and 304 is cylinder number 4.
Code 134 is for a dead O2 sensor and code 1124 is brand specific, for your car it means the fuel system is too lean.
Code 134 could be a faulty sensor or a wiring problem, and it could cause the other codes. Or the code 1124 could be a fuel pressure problem and that could also cause the other codes.
I would probably start with checking the fuel pressure and for vac leaks, then check the sensor to see if it is working.
The cylinder miss codes could be fuel problems or ignition related.

P1136 NISSAN - Intake Valve Timing Control Solenoid Valve Circuit Bank 2

Possible causes- Intake valve timing control solenoid valve bank 2 circuit is open or shorted.
- Intake valve timing control solenoid valve bank 2 circuit connectors
- Intake valve timing control solenoid valve bank 2
P1124 NISSAN - Throttle Control Motor Relay Circuit Short

Possible causes- Throttle Control Motor relay harness is open or shorted
- Throttle Control Motor relay circuit poor electrical connection
- Fualty Throttle Control Motor relay

P1124 = LONG TERM FUEL TRIM ADDITIVE, AIR SYSTEM TOO LEAN
P1128 = LONG TERM FUEL MULTIPLICATIVE, SYSTEN TOO LEAN

I would start with checking fuel pressure, possible the pump or regulator could be faulty.

P1124 - Throttle Position Sensor Out Of Self Test Range
P1124 = Long Term Fuel Trim Additive, Air System too lean

Shoulda gone to HMAservice.com. It's free and has the correct codes for your Hyundai.

Good luck.

Both are pointing to a lean mixture which would explain the misfiring on acceleration. First thing I'd do is have fuel pressure tested, to make sure it's up to spec. If fuel filter hasn't been changed recently, that would also be a good place to start, and if no improvement, have pressure tested. That will tell you if pump is getting weak.

I did some research because the P1128 is an odd code for Hyundai and I couldnt find a lot of information on it, but I found two things that may help and neither point to the fuel pump.

1. P1128 in Hyundai refers to the Mass Airflow Sensor or MAF being defective.
2. There is a TSB from Hyundai, TSB 01-36-022, but I wasnt able to ascertain if that was a specific TSB for the MAF or if it was information on how to test the MAF or some other information.

P1124 seems to be a related code as well but I could find little on it. P1124 in a Subaru is an issue with the Throttle Position Sensor or TPS, but I could not confirm that for Hyundai.

My first suggestion would be to check your air filter and if it has not been changed in a while or is really dirty, then change it as a restriction in air flow might be mistaken by the computer as a problem with the MAF.

Your TPS Sensor is going bad. P1124 is Throttle Position Sensor out of Range. These are easy to change out (2 bolts/screws) and are usually less than 50 bucks at your local auto parts store. Good luck to you and thanks for using fixya!

Sincerely,

JC