Smog Help
Thread Starter
Instructor
Joined: Feb 2005
Posts: 195
Likes: 0
From: Roseville CA
Smog Help
Ok guys had my tuner retard timing to pass sniffer but did not pass because on the way there had check engine light come on , i went ahead and reset. The code was PO104.Tuner removed rear sensors per HP Tuner. Car would not pass because monitors needed to clear. I have driven the car for 200 plus miles and have check weekly on monitors but three will not clear, Heated Oxygen Monitor,Evap Monitor,and a Catalytic Converter Monitor. Why are these not clearing,Never had these fail before.Went back to smog today Monitors still not clear.Present code on DIC is PO430 TWC System Low Efficiency Bank 2. So does the rear sensors need to be turned back on for the Monitors to clear . If not what is my next option. Car only has Kooks and Vortek CAI.
Last edited by sacstyl; Oct 3, 2007 at 03:07 PM.
Burning Brakes
Joined: Mar 2003
Posts: 1,156
Likes: 2
From: Arlington VA
I am by no means an expert in this area but when you say monitors, I assume you mean history. I believe you have to go through a certain number of drive cycles to clear the code history. You might do a search as I remember reading a detailed post about how to go about completing the drive cycle to clear the code history.
Another approach might be to simply disconnect the battery for a short period and re-connect. I cannot remember if it is for 10 or 20 Minutes but I believe this will clear the code history as well.
I am sure others with more experience in this matter will chime in. Good luck with it.
Another approach might be to simply disconnect the battery for a short period and re-connect. I cannot remember if it is for 10 or 20 Minutes but I believe this will clear the code history as well.
I am sure others with more experience in this matter will chime in. Good luck with it.
Racer
Joined: Aug 2005
Posts: 361
Likes: 1
From: Montara Ca
Like SUPERCRUZ I am by no means a expert on this so I may be just talking out of my a** . The OBD II system check is still looking for a pass/fail state on the catalytic converter’s efficiency so if the rear O2’s are turned off it can never clear that diagnostic check, it just wont throw the check engine light due to low cat efficiency. I don’t know why turning off rear O2’s would throw a Evap code, that may be another problem. I think your going to need to turn your rear O2’s back on or get a set of O2 simulators although they may be illegal now you could still find a set on CF used parts board. I’ve basically got the same set up as you…LG street’s, Vortex CAI, LS6 intake. I use to throw the TWC System Low Efficiency Bank 1 or 2 sometimes which would clear on its own after a few drive cycles meaning it had passed the periodic OBD II system check. Had to get it smoged this year and it was failing for high HC at 750 rpm. Got it tuned by Rick @ Synergy (Newark, CA) and it passed with flying colors and has not thrown a TWC System Low Efficiency code since. Obviously you got a smog tech willing to over look the LT and CAI other wise you’re not going to pass the visual. Good luck and let us know how it turns out.
Safety Car
Joined: Sep 2003
Posts: 3,692
Likes: 5
From: Hayward CA
My question is...... why would your tuner turn off the rear O2 sensors? There's no way you're going to pass with those off. PM me who your tuner is, and I'll send you some info on who and where to take your car.
Melting Slicks
Joined: Oct 2006
Posts: 2,236
Likes: 0
From: Suisun City Ca
You dont actually turn the sensors off you just tell the computer there is no error you must do this when running headers or it will throw o2 codes. For some reason he is not able to run more than one series of monitors. As of now he has a tune in the car that has all of the same codes turned off as your car does when you passed smog! His secondary air monitors are not running either for some reason
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Racer
Joined: Jul 2006
Posts: 285
Likes: 1
From: Placentia CA
All it should take to flag the 02 heater monitors is two cold starts as long as all 4 heaters are ok. Obviously all 4 sensors have to be in place and connected. Make sure your tuner has NOT killed the codes: P0135 – P0141 – P0155 and P0157. After a few cold starts and 200 miles it should either flag the monitor or set one of the codes below for a bad O2 heater. Maybe it just has a bad heater in one of the sensors.
P0135 = Left front sensor P0141 = Left rear sensor
P0155 = Right front sensor P0157 = Right rear sensor
As far as the cat monitor see if you’re O/S supports the parameter {C3210}. That’s the number of tests that the cat must pass before the cat monitor will pass. Usually this is set to 6, if you set it to 0 the cat monitor passes as soon as you turn the key on. Not sure on a 99 as the oldest C5 I’ve played with was an 01. You almost always have to kill the codes P0420 and P0430 if you don’t have the stock cats but here again if you can set {C3210} to 0 then it won’t matter.
Evap monitors can take forever to pass but remember having just one monitor not passed yet will not cause you to fail. If you can get the other 2 to pass don’t worry about the evap monitor.
P0135 = Left front sensor P0141 = Left rear sensor
P0155 = Right front sensor P0157 = Right rear sensor
As far as the cat monitor see if you’re O/S supports the parameter {C3210}. That’s the number of tests that the cat must pass before the cat monitor will pass. Usually this is set to 6, if you set it to 0 the cat monitor passes as soon as you turn the key on. Not sure on a 99 as the oldest C5 I’ve played with was an 01. You almost always have to kill the codes P0420 and P0430 if you don’t have the stock cats but here again if you can set {C3210} to 0 then it won’t matter.
Evap monitors can take forever to pass but remember having just one monitor not passed yet will not cause you to fail. If you can get the other 2 to pass don’t worry about the evap monitor.
Le Mans Master
Joined: Aug 2003
Posts: 9,298
Likes: 4
From: American Canyon Lethal Injection
You dont actually turn the sensors off you just tell the computer there is no error you must do this when running headers or it will throw o2 codes. For some reason he is not able to run more than one series of monitors. As of now he has a tune in the car that has all of the same codes turned off as your car does when you passed smog! His secondary air monitors are not running either for some reason
