In the FSM it says that P0420 and P0430 can be caused by air or exhaust leaks. So does this mean that P0420 and 430 can cause it to go into limp mode since the ECM treats the fault codes as possible intake or exhaust leaks? It's dumb, because at that point with test pipes it's impossible to know if it is in-fact an intake or exhaust leak or just the fact the o2 are directly in test pipes, the only way to know would be to log it or know the difference between limp mode and normal mode when there is power.

Possible causes:
Three way catalyst 1
Exhaust tube
Intake air leaks
Fuel injector
Fuel injector leaks
Spark plug
Improper ignition timing

But if there is an intake leak why doesn't the AF sensors trigger a code? Because it's not an intake leak? If it is an exhaust leak after the AF sensors, that would make it go to into limp mode because the rear o2s see the leak, but at the same time they are directly in test pipes which triggers the same codes regardless of an exhaust leak or not.

Really dumb ECM ^ or rather dumb programming.

On the Revup P1273 and 1283 meant exhaust or intake leaks or fueling and it was a sure thing it was one of the 3, the rear o2 didn't trigger a code. On the Revup plugging the o2 directly in would trigger a SES light immediately after startup, on this 04.5 it takes over 20 miles, even though the codes are pending.


Either way, my own conclusion is that AC311 and 04.5s and below are just dumb.

 

Yea I think they just try to cover everything... would be nice if there was a % of possibility with each possible cause lol.

 

djamps, do you have anything to add at this point, how have things been?


I got 2 or 3 of these codes after tuning and towards the end of the year (2012) nothing since, but i'm not really sure what i was logging to see if i had the same correction issue.

I've just received a tune with the rear sensors turned off, but i couldn't remember if that was an effective 'fix' or whether actually unplugging them was needed.

 

All sensors still in their normal locations, no spacers or anything and all is good. I get cat codes pretty much constantly but I've disabled them. Also found out recently that disabling the cat codes won't cause failed emissions here in MD . Happy camper.

If you get anything but cat codes, you either have a tuning issue or a leak. Or maybe bad sensor.

 

Yeah, they're just the cat codes.

The only thing i care about is the rich problem we were discussing, i need to make sure this isn't happening.
Would you mind letting me know exactly what i should be logging and checking for please? (under what conditions etc)



I don't really want to hack the 'built in' anti foulers off my ART pipes if i can help it....


I'm assuming it's not actually possible to disable the rear sensors with Uprev, merely stop the code from being thrown?


I messaged Onagao, but i haven't seen him active since last June His last messages were that it was fixed after physically unplugging the rear sensors, but no full confirmation like a month later or something.

 

After over a year of no code, I am getting P2A03 again AFTER I removed my before the muffler exhaust cutout. Of course I need to pass freaking smog in May. FML.

 

THe most obvious symptom of the rear-o2 issue is low MPG and lean codes (even tho it actually runs rich). Outside of hooking up an A/F meter and watching it while you drive you don't have much else to go on.

 

So yeah, i'm not getting lean codes, i'm getting rear sensors not working correctly, which my tuner has said they're already disabled in the ROM i'm using.... I've also not had codes in a few months, but that could be that it only ever happened when driving longer distances.