Can anyone here help out with these codes? They keep coming back even after I reset them. I have not done anything to try and correct them, as I don't know where to start.

I have run the codes and the P0420 is bank 1 cat inefficiency, and the P0456 is small evap leak.

They come together. The vehicle has been running horribly lately, ever since these codes started popping up. These codes were not present before the summer months. The vehicle sounds loud now, like a valve tick to me. Oil level is good, and condition is still pretty clean. We use synthetic every 3k.

We had plugs and air filter done in late March.

 

anyone? it's back again...... it seems that if I add a qt of oil, it gets better, for like a week......

not that we are going through a qt a week, but it does seem that we are low a lot, not low, just not full..... always above the add mark, but then I add a qt or so

there are no oil leaks, and the vehicle does see a lot of mileage..... roughly 3k a month...


same codes this time, also added a cyl 2 misfire

 

Sounds like you are loosing compresson on at least one cylinder, probably due to worn piston rings. That's where your oil is going, it's blowing by the rings and going out the exhaust. Why don't you call your local dealer and see what they tell you about those codes? I think there emmision system related. That could be why the engine is running rough.

 

U have a bad cat converter that's the 420 the other one is a cracked rubber hose in the evaporative emissions system

 

what do you think about it possibly being a timing issue?

the vehicle has like 140k plus and I don't think the belt has ever been replaced

that would definitely knock out the tapping noise I think that I am hearing or might?

 

u would have misfires and a lot more issues then a 420 code if u had a stretched belt. look up the deff of a 420

P0420-CATALYTIC 1/1 EFFICIENCY
When Monitored: Engine Run time greater than 90 seconds. Engine Coolant greater than
70°C (158°F) Vehicle speed greater than 20 MPH and less than 55 MPH. Engine Speed
greater than 1216 RPM and less than 1952 RPM.
Set Condition: As catalyst efficiency deteriorates, the switch rate of the downstream O2
sensor approaches that of the upstream O2 sensor. If at any point during the test the
switch ratio reaches a predetermined value a counter is incremented by one. One Trip
Fault.
POSSIBLE CAUSES
GOOD TRIP EQUAL TO ZERO
VISUALLY INSPECT CATALYTIC CONVERTER
EXHAUST LEAK
ENGINE MECHANICAL CONDITION
AGING O2 SENSOR
CATALYTIC CONVERTER

 

we do occasionally get a misfire code as well....

we also had a code of P0508 once

 

ok. so time to revisit this..... pacifica has recently failed smog inspection.... could it be a bad o2 sensor or sensors? trying to avoid doing cat or cats, but will if needed.....




same codes, p0420 and p0456 showing up. also had a p0306... I knoe the p0306 is a cyl 6 misfire.....






if there is leaking rings, is there anything I could do temporarily to make it work? the vehicle just needs to get us through the end of the year... but it needs to pass smog first....

 

ok, so a little bit of an update.....


my wife showed me her smog sheet today.....


she passed the emissions portion....


the only thing she did not pass was the obd readiness?

 

because u erased teh codes? pr disconnected the battery?