are you sure you passed in past on the same exhaust and the same tune?

 

100% sure.

 

Some states have apparently begun changing the test to better look for mods to the ECU. If anyone is leading the way it would be Cali. Having the O2 shutoff can be spotted but supposedly changing the level at which the secondaries trip gets around that. This is from word on the street so not gospel, thankfully my state hasn't done this.

 

Changing the secondary 02 reading can prevent a CEL for cat efficiency codes, but readiness is another issue. Many people have had a very hard time getting the readiness to reset after the battery has been disconnected...From what I have seen, it can taker a lot of drive cycles to make it happen...

 

my experience ( twice) is "still" that the drive cycle reset works as it is supposed to. and while easy to screw it up as it is an extremely "precise" protocol and if you go over 40mph in the first portion it's game over, back to start again! and i'm sure 996twinns did it properly? though how one can drive for ten mins on the 118 fwy @ 40 mph is another story! lol so it must be an o2 or something. the obd readout would tell the story. all one needs is a handheld reader and it'll say which portion is failing.. no?!

also, it must be followed to the letter to reset properly.

 

umm rear o2 sensors off? after tune?

 

This seams to be an epidemic among cars with a tune and exhaust. I had to flash back to stock to past the test. I'm not sure what is going on with the tunes the tunes that cause this but it's a pain in the ***.

 

in terms of tunes its usually the rear sensors are turned off by the tuner and this causes a failure when testing. it seems the op had passed before with the same setup he currently has and now fails. that leads one to diagnose a hardware issue not a software issue

 

i've obd tested 4? (iirc) separate times on two flashed cars and never an issue re the tune. i don't believe they are changing the criteria out here, it's about as stringent as it can be.

readiniess montitors are a whole different can of worms, and rarely have to do with the tune the exception being 32;'s point. but who does that and why? i guess the rear 02's are off for a more free flowing exhaust?? i read epl does or did? my cargraphic tune, which is as old as mud.. never an issue, and i last tested with klines 200 cel cats which are in a box somewhere guess i'll switch that up soon enough lol

 

As I understand it turning them off is one way and can be caught in the past. Another way it changing the level at which a monitor trips and this might be something getting caught now? It's done in a tune for folks to run high flow cats that aren't as efficient as stock, no cats, or the tune is just richer and trips.

 

got it thx. yeah, if they're "off" no doubt "they" will know.

 

the KEY to resetting readiness monitors is a cold engine. you start early am with a cold engine and run thru the set. then park it. next day repeat. set. next day repeat. this should do the trick. only once a day once the motor is hot your done for the day. its tough for most to do but thats the key.
turning off the rear sensor keeps the dme from tossing a code when running catless or 100 cel cats. this way the sensors can't see theres little to no change from the front sensors. obviously when emissions are factored in it changes things.

 

I flashed back to stock and fitted my stock exhaust. Life's too short to try to get around Cali smog laws.

 

thx for the clarification. i had 02 sensor codes and just swapped them out and all is fine since and i run decat. but my sensors went bad just about the time i installed a different 200 cell cat exhaust coming from a modded oem.

as for the readiness reset, i've either been very lucky or i don't know what. i've had to do it a couple of times. i didn't realize the sensitivity of the process, and consequently tried to do it during traffic ( duh ) and the only impediment was traffic impeding my ability to maintain the speeds called for in the reset protocol ( which is the same as bmw's curiously )..it's tricky and very easy to screw it up..never over 3k rpm etc etc.

but once i tried it at 4 am on streets with no traffic, it immediately ( well, the 20/30 mins whatever ) reset and i was good to go. i was fortunate in that my smog guy gives me a headsup on stuff before we actually begin the process in earnest, so i can ( and do ) fix whatever might log a fail since they are basically plugged into the "state" logging the car. out here any "fail" that gets logged, requires you to get with the bar referee and plead your case etc. fortunately i hedge my bets by being extra prepared.

also.. at the risk of repeating myself to anyone in kali? have a code reader PRIOR to even pulling into a start test station. don't let THEM tell you the car isn't "ready".

 

I will give it another try again tomorrow.

Used the cruise control for the first time since owing the car last week.

Look for the 996Turbo in the slow lane at less than 60MPH on the 118 Ronnie Reagan freeway.