[2002 Outback P0420 code AFTER new CAT converter]

8 minutes ago, brus brother said:

I have had P0420 on my 05 OB for the last ~100k miles.

I live in an emissions testing state.

I have tried inserting the resistor trick on the O2 signal wire but while the P0420 went away, I started throwing P0298 immediately. Uninstalled the resistor and back to the P0420.

While P0298 comes on almost immediately after clearing the codes, I can clear the P0420 and then have enough time to get all the systems "ready" to pass inspection.

Procedure for readiness:

I use an old Autel Maxiscan LINK listed from China for cheap if you can wait for delivery of there are similar US sellers for $18-20

It's cheap enough to keep in the car and plug into the OBD port without fiddling around with opening programs on your phone to mate with the other types. But, both types will do the same thing.

Best done with 1/2 tank of gas

1. Clear codes

2. Start car without stepping on the gas (it will take a few cranks as the ECU is starting from scratch).

3. Let car idle for 15 minutes without touching the gas

4. Drive car about 10-15 minutes at highway speed (55 mph) trying to keep speed constant (no braking or hard acceleration)

5. Check for system readiness and if all set as ready, drive to inspection station.

I check for inspection stations nearby and plan my route accordingly. Last time it took a few tries to hit the sweet spot but I am now good for another year and a hlaf.

I have been doing this for the past 7 years through three inspection cycles.

I'm not willing to play this game. The issue needs to be fixed. There is a cause and it can be found properly.

[2002 Outback P0420 code AFTER new CAT converter]

Need some serious help. I have to get this fixed. This car is going to my girlfriends kid when he passes his drivers test and it has to pass inspection. Turning off the code just before inspection is not the answer.

2003 forester x-  I have had P0420 code since June(ish) 2019. No other codes except the occasional fan rationality check code which I'm pretty sure I resolved with the new Coolant temp sensor. 

An engine with 120K(ish) was put in the car in December of 2018 after the original blew up from catastrophic head gasket failure. It has about 155K(ish) on it now.  My odometer says 310K it read 275K when the engine was replaced. 

Since  first getting P0420  I have done the following:

New PCV valve, new NGK spark plugs, new NGK wires, New fuel filter in the tank and under the hood, new IAT, new coolant temp sensor,  new denso A/F sensor and 02 sensor, new eastern CAT.  No exhaust leaks and from what I can tell no vacuum leaks. Most of the vacuum line were replaced anyway. 

I have done the seafoam intake cleaner. I did the high concentrate on a low tank of gas injector cleaner twice. 

My generic scanner says Cat monitor incomplete. 

Fuel economy seems ok. It's not excessively bad. Performance is decent.  Don't know about emissions since my state doesn't do vehicle inspections. My profile says I'm in NC but actually live in SC. 

 

The Scan tool shows the A/F sensor at 2v +- and the 02 Sensor bouncing but hovering at .5v. I have read that the A/F sensor is supposed to read .1-.9 and fluctuate and the mixture is adjusted by the ECM. However, the scantool shows you a voltage that is read from the ECM concerning the A/F sensor and converted so I the 2.1- 1.9 ish readings are good. 

Freeze frame from the last code set after resetting. 

 

RPM 2288

Load calc % 12.99

MAP Hg 12.4

Coolant temp 192

ST Ftrm -0.06

LT Ftrm 7.8

MPH 57

Closed loop