Unstable idle, p0420 p0430

[Jmxtwiztid]

Figure its about time to join up, ive scoured this forum countless times and found information that always helps. This one has me at a loss though, please share your input!

2005 Ford Taurus 3.0 OHV

Symptoms:
Unstable idle (690-790) Needle bounces up and down
P0420
P0430
Small amounts of oil in upper plenum

Parts changed:
IAC
TPS
Intake plenum gaskets
IMT Oring
PVC Valve
Crankcase vent tubing
EGR connecting tube Oring
DPFE Sensor

Work:
Cleaned MAF
Checked all vacuum lines

EGR held 6 on the mityvac
Applied vacuum to EGR while idling, started sputtering, idle erratically

(I did the above to to check the operation of the EGR)

Freeze frame data p0420:
Fuel System: Closed loop
Load value: 65.8%
Coolant Temp:165 F
Short Term fuel trim 1: 0.8%
Long Term fuel trim 1: -2.4%
Short Term fuel trim 2: 3.1%
Long Term fuel trim 2: 4.6%
RPM: 1705
Speed: 46 mph
Ignition timing advance: 35.0
Intake air temp: 59 F
Air flow rate: 2.69 lb/min
Throttle position: 25%
Oxygen sensor 1 bank 1: 0.815v
Oxygen sensor 2 bank 1: 0.720v
Oxygen sensor 1 bank 2: 0.295v
Oxygen sensor 2 bank 2: 0.165v


Fuel pressure at idle 39-40

I'm at a loss as to what else it could be, I may have done more and forgotten it's been about a week so far, any input is appreciated!

[Jmxtwiztid]

I don't have any other symptoms that are noticeable other than the unstable idle, runs fine in the city and on the hwy at 80+, so I don't think the problem is actually the cats, I'm no expert though.

[Breeves002]

Still seems like a bad IAC. How often do you change your oil? What weight oil do you use/what oil filter (or where do you go to get it changed?)?

[WJC]

What is the long term fuel trim at idle with the engine fully warm?

[Jmxtwiztid]

5w20, motorcraft filter, every 4000. I should clarify that it used to jump alot more 2-300 rpms at a time, then after the new IAC 50-100 rpms at a time it helped a good bit. Ill go check on that WJC.

[Jmxtwiztid]

Engine Temp: 201 F
Long Term fuel trim1: 14.8%
Long Term fuel trim2: 18.7%
RPM: 752
Fuel Rail Pressure: 46PSI
Fuel Level Input: 40.3%

[Jmxtwiztid]

Also, bank 1 and 2 (p0420 & p0430) do those refer to the y pipe as bank 1 and the rear converter as bank 2?

[sheila]

Bank#1= firewall bank (po420). Bank#2= radiator bank (po430).

[Jmxtwiztid]

Ok so both of those are on the y pipe and don't need to worry about the rear? Sorry my experience is more with diesel so i dont really know much about cats or emissions. Think I just got confused, there are only two cats on the car, one by the radiator and one under the car right before the resonator right?

[WJC]

Originally Posted by Jmxtwiztid

Engine Temp: 201 F
Long Term fuel trim1: 14.8%
Long Term fuel trim2: 18.7%
RPM: 752
Fuel Rail Pressure: 46PSI
Fuel Level Input: 40.3%

OK those are high, you're running lean at idle. I think you still have a vacuum leak.