Disappointing dyno post modifications; comments?
07-25-2016, 09:11 PM
#51
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Thread Starter
Join Date: 02-08-2013
Location: Upstate, NY
Posts: 36
So the car's running great (except I cannot get the cat back to stop banging SOMETHING - but that's not a performance issue) but I cannot get the Evap monitor "ready". Everything else is clear except Cat and EVAP and the Cat is switched off so I need the Evap to come through.
In doing some searches I find a lot of complaints about GM products taking WEEKS to set their Evap ready state. I'm nearly a full month overdue for inspection. Extremely frustrating to be in this position :/
But, again, the car has never ran so well. Once I pass inspection, I'll take it to the dyno for a reality check.
In doing some searches I find a lot of complaints about GM products taking WEEKS to set their Evap ready state. I'm nearly a full month overdue for inspection. Extremely frustrating to be in this position :/
But, again, the car has never ran so well. Once I pass inspection, I'll take it to the dyno for a reality check.
07-25-2016, 09:28 PM
#52
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Join Date: 01-23-2009
Location: Fredericksburg, Virginia
Posts: 24,696
Unless you can do a "drive cycle" exactly perfectly, and I don't think it is possible, it takes like 25 cold to warm up cycles. Its been a while, but I think 25 is the magic number.
It is rumored that a Tech2 can force a drive cylcle in the shop.
The EVAP will not run if there are any pending or current codes.
I thought somebody said NY allowed 1 not ready.
It is rumored that a Tech2 can force a drive cylcle in the shop.
The EVAP will not run if there are any pending or current codes.
I thought somebody said NY allowed 1 not ready.
07-25-2016, 10:19 PM
#53
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Join Date: 05-01-2014
Location: California
Posts: 7,809
Here's how to complete a drive cycle. The one that seemed like it would be difficult is decelerating from 55 to 20 without shifting or touching the clutch or brake.
From OBD II Drive Cycle (reset car diagnostic monitors )
Generic OBD II "Drive Cycle"
Most OBD II ("On-Board Diagnostics II") diagnostic monitors will run at some time during normal operation of the vehicle.
However, to satisy all of the different Trip enable criteria and run all of the OBD II diagnostic monitors, the vehicle must be driven under a variety of conditions. The following drive cycle will (theoretically) allow all monitors to run on (??) vehicle. (Note: Drive cycle specifics vary by vehicle!)
Ensure that the fuel tank is between 1/4 and 3/4 full.
Start cold (below 86°F /30°C) and warm up until engine coolant temperature is at least 160° F (typically requires at least one minute; up to 3 minutes).
Accelerate to 40-55 MPH at 25% throttle and maintain speed for five minutes.
Decelerate without using the brake (coast down) to 20 MPH or less, then stop the vehicle. Allow the engine to idle for 10 seconds, turn the key off, and wait one minute.
Restart and accelerate to 40-55 MPH at 25% throttle and maintain speed for two minutes.
Decelerate with (I think they mean without - RJ)using the brake [or the clutch!] by coasting down to 20 MPH or less, then stop the vehicle. Allow the engine to idle for 10 seconds, turn the key off, and wait one minute.
General Motors (specific) OBD II Drive Cycle
Performing a GM OBDII Driving cycle:
Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 122°F (50°C) and within 11°F (6°C) of the ambient air temperature at startup.
Do not leave the key in prior to the cold start or the heated oxygen sensor diagnostic may not run.
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.
Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until 55mph (88km/hr) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.
Hold Steady Speed. Hold a steady speed of 55mph (88km/hr) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed.
Decelerate. Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 20 mph (32km/hr). During this time the EGR, Purge and Fuel Trim diagnostics will be performed.
Accelerate. Accelerate at 3/4 throttle until 55-60mph (88-96 km/hr). This will perform the same diagnostics as in step 3.
Hold Steady Speed. Hold a steady speed of 55mph (88km/hr) 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.
Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.
Further useful information:
Understanding On-Board Diagnostics (from the Illinois EPA):
Page Not Found
from "A Guide to the Illinois Vehicle Emissions Inspection Program" (March 2005 revision)
[ Page Not Found ]
This page: January 9, 2005; compiled from online sources.
Here's another that says the same: How To Complete a Chevy Cavalier Drive Cycle
From OBD II Drive Cycle (reset car diagnostic monitors )
Generic OBD II "Drive Cycle"
Most OBD II ("On-Board Diagnostics II") diagnostic monitors will run at some time during normal operation of the vehicle.
However, to satisy all of the different Trip enable criteria and run all of the OBD II diagnostic monitors, the vehicle must be driven under a variety of conditions. The following drive cycle will (theoretically) allow all monitors to run on (??) vehicle. (Note: Drive cycle specifics vary by vehicle!)
Ensure that the fuel tank is between 1/4 and 3/4 full.
Start cold (below 86°F /30°C) and warm up until engine coolant temperature is at least 160° F (typically requires at least one minute; up to 3 minutes).
Accelerate to 40-55 MPH at 25% throttle and maintain speed for five minutes.
Decelerate without using the brake (coast down) to 20 MPH or less, then stop the vehicle. Allow the engine to idle for 10 seconds, turn the key off, and wait one minute.
Restart and accelerate to 40-55 MPH at 25% throttle and maintain speed for two minutes.
Decelerate with (I think they mean without - RJ)using the brake [or the clutch!] by coasting down to 20 MPH or less, then stop the vehicle. Allow the engine to idle for 10 seconds, turn the key off, and wait one minute.
General Motors (specific) OBD II Drive Cycle
Performing a GM OBDII Driving cycle:
Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 122°F (50°C) and within 11°F (6°C) of the ambient air temperature at startup.
Do not leave the key in prior to the cold start or the heated oxygen sensor diagnostic may not run.
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.
Accelerate. Turn off the air conditioner and all the other loads and apply half throttle until 55mph (88km/hr) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.
Hold Steady Speed. Hold a steady speed of 55mph (88km/hr) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed.
Decelerate. Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 20 mph (32km/hr). During this time the EGR, Purge and Fuel Trim diagnostics will be performed.
Accelerate. Accelerate at 3/4 throttle until 55-60mph (88-96 km/hr). This will perform the same diagnostics as in step 3.
Hold Steady Speed. Hold a steady speed of 55mph (88km/hr) 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.
Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.
Further useful information:
Understanding On-Board Diagnostics (from the Illinois EPA):
Page Not Found
from "A Guide to the Illinois Vehicle Emissions Inspection Program" (March 2005 revision)
[ Page Not Found ]
This page: January 9, 2005; compiled from online sources.
Here's another that says the same: How To Complete a Chevy Cavalier Drive Cycle
07-25-2016, 10:25 PM
#54
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Join Date: 05-01-2014
Location: California
Posts: 7,809
07-25-2016, 10:29 PM
#55
Member
Thread Starter
Join Date: 02-08-2013
Location: Upstate, NY
Posts: 36
Unless you can do a "drive cycle" exactly perfectly, and I don't think it is possible, it takes like 25 cold to warm up cycles. Its been a while, but I think 25 is the magic number.
It is rumored that a Tech2 can force a drive cylcle in the shop.
The EVAP will not run if there are any pending or current codes.
I thought somebody said NY allowed 1 not ready.
It is rumored that a Tech2 can force a drive cylcle in the shop.
The EVAP will not run if there are any pending or current codes.
I thought somebody said NY allowed 1 not ready.
I have no pending codes at all. I check (but do not alter!) the darn thing daily.
NY follows federal regs in this case and allows 1 pending monitor. I will "always" have Cat "not ready" because of tune. Thus I'm left at the mercy of the Evap monitor
07-25-2016, 10:32 PM
#56
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Thread Starter
Join Date: 02-08-2013
Location: Upstate, NY
Posts: 36
I think we've exceeded the original thread's intentions, but I certainly appreciate the feedback. I'll try the expressly written drive cycle and see what happens!
07-26-2016, 04:12 AM
#57
Senior Member
Join Date: 04-26-2009
Location: City of Champions
Posts: 666
That specific number (25 cold starts) is crazy. Yeah, that's clearly part of the problem.
I have no pending codes at all. I check (but do not alter!) the darn thing daily.
NY follows federal regs in this case and allows 1 pending monitor. I will "always" have Cat "not ready" because of tune. Thus I'm left at the mercy of the Evap monitor
I have no pending codes at all. I check (but do not alter!) the darn thing daily.
NY follows federal regs in this case and allows 1 pending monitor. I will "always" have Cat "not ready" because of tune. Thus I'm left at the mercy of the Evap monitor
The tune can be easily changed so that the 'cat' is always ready...
07-26-2016, 07:31 PM
#59
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Thread Starter
Join Date: 02-08-2013
Location: Upstate, NY
Posts: 36
The impression I got from ZZP was that it was a sort of "de facto" set up. They'd happily enable it for the cost of S/H but that also leaves me without a car for a while and I can't have that until my old Jeep gets back on the road... A lot of contingencies!
08-15-2016, 12:30 PM
#60
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Thread Starter
Join Date: 02-08-2013
Location: Upstate, NY
Posts: 36
After A LOT of miles... The cat monitor was ready. Yes, the cat... I don't get it. Evap never came up, but as soon as I saw there was only one monitor out (and no codes) I brought back to the shop. Since he'd already done everything else, he just pulled it in, hooked it up to the NYS machine, ran it and printed my sticker... Good for a year now.
Evap STILL hasn't come up, BTW... But the worst is over at this point. I am legal! Yay; I can move on!
Evap STILL hasn't come up, BTW... But the worst is over at this point. I am legal! Yay; I can move on!