You need to re-enable them.

I'm pre tune with ART pipes and running fine, i cannot repro the fault. I will see what, if anything, happens after the tune, but either way, the sensors need to be reading something.

For now, you can unplug the rear sensors without changing anything else and see what happens.

UPDATE:

Had new working downstream o2 sensors installed and re-enabled. So far so good. Not consuming fuel like crazy @ closed loop operation like before. No SES/CEL yet. Been about a week. Hopefully I can get emissions done in July w/out complications.

Sounds good to me, keep us updated :)

Any updates? I just purchased a Interlagos Fire 06 and installed art pipes and catback and now this.. When I had this set up on my 03 I was throwing a 02 code but now I hear about this PA200 gremlin that only happens on 06-08... Wtf lol after reading all pages was wandering if any of the theory's worked.

Unplugging the rear sensors worked, but don't worry about it if you're not having it.

So just leave them unplugged??? :dunno:
I saw where someone did that but how does this technically FIX the problem?

The problem seemed to relate to the rear sensors not giving a reading the ecu wanted, so it tried to correct to the bad reading.

Are you having this problem?

If you got the VQ35HR, I'd suggest keeping the downstream rear o2 plugged in. I had mine unplugged and disabled and it caused some fuel consumption issues because it kept thinking not enough exhaust gasses were getting through the exhaust, tricked ECU into thinking car needed more and more fuel. My mpg went down to ~18 mostly highway driving.

I had them re-enabled and plugged in working sensors and no SES lights as long as I am not cruising at a consistent speed for an extended duration of time.

This is true. Even non-foulers and other tricks will negatively affect mileage.

Someone has already stated their problem was fixed after unplugging the rear sensors, not by disabling them, that's different.

Update, and post tune, during the winter, i threw at least 2 codes, if not 3.

I still cannot repro reliably and i haven't seen it for some months now, however, i *think* i'm running the over corrected fueling still, need more info to check.


I have a 2004.5 motor, as it seems it's affecting the different engines differently.


I just received a tune that has the rear sensors disabled, i do not recall as to whether this is enough or if they need to be unplugged.



If i could get the settings i need to check in Cipher from someone, then i can do a before and after to see if it's making any useful difference.

Woes of going test pipes and being ocd about dash lights :X

I'd say leave sensors enabled and plugged in.. I've not had any CELs for a long time. Last time was from a road trip from Dallas to Houston where I cruise controlled for > 1 hour. CEL eventually came on but it went away after like 1000 miles normal driving.

Right, but the problem is not really the CEL, so much as the arsing around with the fueling that it does, that causes bad perf and poor MPG :(

So i thought i'd do some more digging tonight, i pulled up my logging from the time these codes were thrown.

However, i can't remember if this is from when the code was present, or just around the same time. I also can't get excel to plot enough points from the logs, i'm only getting something like 12000 lines in which isn't showing enough.

My codes are more 'worrying' though, they're not the codes i thought they were, each CEL i had, threw these codes:

P0139 & P0159, O2 Sensor Circuit Slow Response (Banks 1 & 2)

Followed by:
P1146
P1166
P1147
P1167

All of which are Heated O2 Sensor 2.