In IL, the test is through the OBDII (not sniff).

OBDII read gives 2 "Not Readys" - Evap and O2. Car is throwing no codes to DIC.

I drove car for 3 days after 2nd failure to got the computer through it's cycle. Still NG.

Car has been modded, but has cats, and again this seems to be computer based, as I really haven't got to the test, it doesn't get through the pre-test.

Thoughts?

 

Try this...




General Motors Driving Cycle
A complete driving cycle should perform diagnostics on all systems. A complete driving cycle can be done in under fifteen minutes.

To perform an OBDII Driving cycle do the following:

Cold Start. In order to be classified as a cold start the engine coolant temperature must be below 50°C (122°F) and within 6°C (11°F) 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.

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 88km/hr (55mph) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.

Hold Steady Speed. Hold a steady speed of 88km/hr (55mph) 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 32km/hr (20 mph). During this time the EGR, Purge and Fuel Trim diagnostics will be performed.

Accelerate. Accelerate at 3/4 throttle until 88-96 km/hr (55-60mph). This will perform the same diagnostics as in step 3.

Hold Steady Speed. Hold a steady speed of 88km/hr (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.

Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.
Reprinted on OBDII web site courtesy of General Motors Corporation
© General Motors Corporation

[ OBD-II Home ]



© 2006 B&B Electronics The OBD-II Home Page is hosted by

 

Run it by Dan at FLP in Naperville. He can delete the codes and fix the issues you're having. He may actually give you some additional ponies by the time he is done.

 

Thanks, will do

 

in NY you are allow two codes of the possible 140 I think.

 

I ran the cycle. tried it again at the emissions hellhole, still no go. I get 2 not readys, 1 on O2. 1 on Evap.

I'm starting to think this has something to do with having only 2 )2 sensors, post LG headers, Cats.

DO I need O2 simulators or something??

 

Oh, yeah.

The PCM determines cat health from the delta between the front and back sensors. Call LG.

 

You might have a bad gas cap gasket. Apply some silicone grease to the cap gasket and see if the evap code goes away. If your failing the test,,,you should have DTC Codes!

Try to read the DTC Codes using this procedure:


This is the absolute best C5 Code web site!!!

http://www.corvettedoctor.com/Code_Main.html

www.corvettedoctor.com

http://www.corvettedoctor.com/index.html

Here is another very good site:

http://www.obd-codes.com/trouble_cod...d-ii-codes.php



BC

 

Not if someone deleted the test for EVAP and the rear O2's when the car was tuned.

 

I have no DTCs.I may try that gas cap thing next time I go. I think they allow 1 "not ready" and I have 2...