and you mention full standalone, i was heavily considering going with aem for tuning, but tuners on here said it did not work well

i would put cats on, but i need to get the hot nitrous burn out of my engine as fast as i can. i had cats on a nitrous motor before and i had bad heat problems. i will also have a cutout before the muffler, so it would be silly to have cats and then a cutout, since getting the exhaust out as fast as i can is a priority.

 

the rear o2's still work without cats when u put them in the exhaust flow. The emissions control gets upset (catalyst codes) but that's it. A/F's are good.

When it's time to pass emissions testing in an obd2 state like MD I put the non-foulers (extensions) back on, enable all emissions codes, drive for 20 miles or so and it passes. It usually takes 50-300 miles until lean codes trip with anti foulers; plenty of time to get thru emissions with flying colors LOL.

 

I have to actually see the cats when I do CA inspection, interesting. Plus I know the smell of a bad cat and a missing cat is worse, EVO guy tried sneak one through once. There is a new OBD II+CAN based smog testing machine coming that I'm pretty sure can detect reprogramming. It will finally read VIN's too. Even my pocket scanner can do that but not my BAR97 POS.

Can you look at your datastream and see if the ECU is still doing the lean/rich injector pulse width switching? I'm thinking there is a default mode that I was never told about.

 

The o2's definitely still cycle. Luckily in MD they don't really do much in terms of visual...

 

So, although not what you asked for, djamps, i did logging on the way to work this morning. It was only about 10 minutes of constant on the freeway, but i saw the A/F's sitting stead about 14.4.

How long constantly cruising do you have to travel before you start seeing the problem? based on your logs.

 

Usually took at least 30 miles until it started happening, I think all the emissions systems have to be in a 'ready' state.

But please tell what year of Z/G you have. We already have evidence that not all years/models behave the same way.

 

i will log mine too when i get it running right

 

30 miles constant? wow, ok, so that's going to be quite the specific condition, i'm assuming you mean constant without any changes at all in that time?

I'm running an '04.5

 

I don't know about constant... whatever it takes to get all the systems 'ready' state like you're about to try to pass emissions.

rear o2 behavior confirmed on an 06.

 

according to the FSM (EC-58) you need almost 11 minutes of constant 53-60mph cruising.

Speed must be in that range.

 

The ready state is a one time thing. Once they're ready/reporting, they don't have to do that again the next time the car is started.

 

Reading now, thanks.

 

Hmm, would like to kind of merge these two threads really, some good info in the other one.

There does seem to be an easier way to re-produce. We don't know if it happens on all cars, but i'd love to know if i can repro it on mine.

 

If disconnecting the rear o2's actually does stabilize things it might be the best thing to do if you have test pipes.

I wonder if them off/unheated in the hot exhaust could damage or foul them up them over time though.

 

Well, they're in extenders/anti-foulers, so i'd doubt it. Being in the cold exhaust would be the only thing, but again, doesn't make sense to.

 

I am having this 04.5 issue which has led me to believe the 04.5 and anything below 04.5 is a piece of ****. Not using non-foulers throws a SES light on my car. If I use 90 degree non-foulers it overcorrects for a lean condition. If I use straight and drilled non-foulers it overcorrects for lean condition again BUT WITH NO CODES - at least that's what I think is happening because it runs shitty as if there is codes.

I have an 05 6 speed sedan with a full Non-Revup swap, new 04.5 ECM and new harness. The Revup ECM never complained like a ***** and took non-foulers and ran hard with no codes and it was ready for full on power after a reset and pulling out of the driveway unlike this 04.5 one which continues to SEVERELY **** me off.

I tried it, it doesn't work. Still runs shitty. But I forgot to clear learned fuel trims.

This is the amount of codes that come up when they are disconnected. Worse than a German car.
P0139,02 Sensor Circuit Slow Response (Bank 1 Sensor 2)
**********
P0159,02 Sensor Circuit Slow Response (Bank 2 Sensor 2)
**********
P1146,Heated O2 Sensor 2
**********
P1166,Heated O2 Sensor 2
**********
P1147,Heated O2 Sensor 2
**********
P1167,Heated O2 Sensor 2

 

This is to be expected. You have to delete the P04x0 codes. If you are throwing other codes with all sensors in the exaust stream then you have another issues like exhaust/vacuum leaks, bad tuning, ect.

 

Yeah i think you're barking up the wrong tree here, you're expecting something no one else even expects.

 

It doesn't throw other codes when the sensors are directly in besides that one for each sensor and it runs shitty, and it throws no codes when they are in with the straight non-foulers but still runs shitty. Throws 1273 and 1283 for AF sensors with 90 degree non-foulers even though those have not been touched.

And any car that is not a Revup will have this issue, all the way up to the 07 automatic G35 coupe. Any one who doesn't have a Revup and who have test pipes and use straight non-foulers have this issue and don't know it because there is no codes. They just think it runs normal when it actually doesn't because they don't know the difference. I do.

 

That's the whole point, it's what he's saying, those codes are because it detects gasses consistent with there being no cats.