2004 LX 470 235k miles, just got p0420 code

[OteyCrisman]

and p0430 is pending.

I just got gas this morning, then drove 15 miles to destination. Upon getting back in car to drive back home, cranked it up and noticed the steering wheel did not automatically move into driving position. I moved it to normal position with the switch. About half way home is when CEL, VSC trac and VSC off lights came on. Car seems to drive normally. Reader gave me p0420 code plus p0430 is pending.

Other info is I just had fan bracket, timing belt, and water pump replaced a month ago.

I'm in a big rush having to get to work now and don't have time to read other threads about these codes... Should I not be driving vehicle until this is sorted or what? Kinda have to to get to work here in a minute, thanks for any help.

 

[OteyCrisman]

Now driving to work it still reads p0420 and for pending it shows p0420 again. No sign of p0430 like earlier. I did not clear the codes on the vehicle earlier. Only cleared the history on the reader before this most recent reading. Don't know what to make of that, just trying to list all relevant details

 

[Aracobuilt]

Most common causes for those codes is faulty catalytic converter(s), exhaust/manifold leak, faulty o2 sensor(s), and faulty wiring.

It is common for the VSC lights to come on when the CEL comes on due to a code.

 

[Aracobuilt]

I would start by making sure that the gas cap is on right if the codes don't go away than I would reset them and see what happens next.

 

[excessive]

start with O2 sensors and go from there

 

[OteyCrisman]

Thanks for the help. Ended up retightening the gas cap yesterday, cleared the codes, and so far none have come back. Hopefully thats all it was! Seems like the code should've turned up again by now, 4 separate trips and about 50 miles total driven since clearing. Nothing even pending shows up currently.

 

[andrewderrick]

gas cap ain’t gonna cause cat efficiency faults, best case 02 sensors, however likely cats or an exhaust leak

 

[OteyCrisman]

gas cap ain’t gonna cause cat efficiency faults, best case 02 sensors, however likely cats or an exhaust leak

Well damn

 

[Coin]

I had the same codes. Replaced the 2 rear O2 sensors and all has been fine for 2+ yrs.

 

[2001LC]

First: Owners manual sates: Never prolong idle engine! Idling loads CATs.

Make sure your engine is well tuned.
Tune:
Radiator fins clean. Coolant system full (no air). Good OEM thermostat. ECT staying above 184f, below 200F.
Good air filter.
Good OEM, MAF sensor.
Throttle body clean.
Correct all vacuum leaks. Including hoses and good PCV valve.
Good OEM oil fill cap, with good seal
Good spark plugs. Make sure all tight.
Engine oil flush. 2 cans BG EPR, 30 mins before hot oil draining.
Add 2 cans of 44K, to full tank of gas.
High (4.5K RPM) RPM HWY runs. AKA: Italian tune.

If CAT codes return. Try CataClean or Sledge hammer.
High (4.5K RPM) RPM HWY runs. AKA: Italian tune.

Still P0420 -30 returning.
Likely cooked CAT. Worth replacing o2s first.