ODB2 Emission monitor reset - Tuning Forum

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ODB2 Emission monitor reset
Friday, December 16, 2011 9:21 AM
I posted this in the maintenace forum, but its prob better suited for here...

Quote:

After the computer has been reset, what driving cycle is needed for the emission monitors to clear so its ready to test again? I found the following:

Quote:

1 - Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 122F and within 11F of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run.

2 - Idle. The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater, Passive Air, Purge "No Flow", Misfire and if closed loop is achieved, Fuel Trim.

3 - Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until 55mph is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.

4 - Hold Steady Speed. Hold a steady speed of 55mph for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed.

5 - Decelerate. Let off the accelerator pedal. Do not shift, touch the brake or clutch. Let the vehicle coast along gradually slowing down to 20 mph. During this time the EGR, Purge and Fuel Trim diagnostics will be performed.

6 - Accelerate. Accelerate at 3/4 throttle to 55-60mph. This will perform the same diagnostics as in step 3.

7 - Hold Steady Speed. Hold a steady speed of 55mph for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst.

8 - Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the brakes or shift gears.



Does that seem extensive or is that accurate? I've done all except the coast from 55+ down to 20. No CEL but system still isn't ready. I'm wondering if I just haven't done the complete procedure or if the way I have HPT setup it will never show ready. I have HPT set so it won't report any errors for the downstream O2 sensor or for catalyst inefficiency since I have no rear cat. The two system monitors still pending are the EVAP and O2 sensor.

Also, does anyone know if reflashing a HPT file resets everything that has tested so far, just like if you unhook your battery, or does it keep the monitors tested as is? Thanks.






12.6 @ 114.6 MPH


Re: ODB2 Emission monitor reset
Friday, December 16, 2011 12:35 PM
Reflashing will erase readiness monitors....



P&P Tuning
420.5whp / 359.8wtq

Re: ODB2 Emission monitor reset
Friday, December 16, 2011 2:56 PM
I had a feeling that was true. So what about as far as the "do not report error" on HPT possibly causing the readiness monitors to never be ready? Again though, I have done all the above procedure with the exception of coasting from 55+ down to 20.




12.6 @ 114.6 MPH

Re: ODB2 Emission monitor reset
Saturday, December 17, 2011 8:32 AM
While unlawful to do, you can set everything to "DO NOT REPORT" and make the readiness monitors "READY".... Guess this kinda turns into a "don't ask, don't tell" type situation....





P&P Tuning
420.5whp / 359.8wtq

Re: ODB2 Emission monitor reset
Saturday, December 17, 2011 9:43 AM
QWK LN2 (P&P Tuning) wrote:

and make the readiness monitors "READY"

You can make the readiness monitors show ready with HTP or do you mean just by the usual driving cycles?




12.6 @ 114.6 MPH

Re: ODB2 Emission monitor reset
Saturday, December 17, 2011 10:53 AM
--Boosted Z-- wrote:

QWK LN2 (P&P Tuning) wrote:

and make the readiness monitors "READY"

You can make the readiness monitors show ready with HTP or do you mean just by the usual driving cycles?


Read the bold text.....





P&P Tuning
420.5whp / 359.8wtq

Re: ODB2 Emission monitor reset
Saturday, December 17, 2011 11:17 AM
I typed the bold text, lol. Thats good news though... how do you do it?



12.6 @ 114.6 MPH

Re: ODB2 Emission monitor reset
Saturday, December 17, 2011 11:19 AM
--Boosted Z-- wrote:

I typed the bold text, lol. Thats good news though... how do you do it?
See my 2nd post.... The one with the





P&P Tuning
420.5whp / 359.8wtq

Re: ODB2 Emission monitor reset
Saturday, December 17, 2011 11:23 AM
So you're saying if you set all DTCs (instead of a select few like I currently have) to do not report, then that makes the readiness monitors show ready?



12.6 @ 114.6 MPH

Re: ODB2 Emission monitor reset
Wednesday, December 21, 2011 7:07 AM
Winner winner chicken dinner. What prize to we have today Bob?



Re: ODB2 Emission monitor reset
Wednesday, December 21, 2011 7:11 PM
Ryan, you're a genius. Thanks guys.



12.6 @ 114.6 MPH


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