Thought I would post a follow-up to my failed emissions test thread. http://forums.corvetteforum.com/zerothread?id=699117 Ga. uses the OBD II diagnostics port to test cars as part of their license plate renewal process. This was the first test done on my car since doing a few mods. The mods list: MMS Stage IIX heads, Comp push rods, Comp cam 224, .566 LSA-114, ARP studs, P&P oil pump, P&P maf and T.B., LGM LT header, ORP’s, O2 sims, Z06 cat-back and Mike’s tuning. I really didn’t expect any problems, but the guy running the test said I did not pass the test. He said to drive the car 2 weeks and return for one additional test at no charge. When I got home I read the report and it said OBD II test results “NOT READY”. The guy gave me a document that told me what to do and what was most likely the cause of the problem. Dead or Replaced Battery…. Sure enough a few weeks before the test I installed an Optima Red Top. I found bits and pieces of information, but nothing that said exactly what was required to get the PCM in a READY state, until I borrowed EFILive from Patches. EFILive had a test called “System Readiness Tests”, I had seen the test several times but never really paid much attention to it until now. After running the test several more times I always had 3 tests that failed with red Xs. I drove the car as much as possible trying to meet the requirements needed to have the PCM become “Ready”. Well guess what, the answer was right under my nose the whole time.
“GMs OBD II Drive Cycle”, takes about 15 minutes, kinda sorta. Bottom line, I hope this help someone else out!

General Motors' OBD-II 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 OBD-II Driving cycle do the following:
1. 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 start-up. 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 88km/hr (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 88km/hr (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 or 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.
6. Accelerate. Accelerate at 3/4 throttle until 88-96 km/hr (55-60mph). This will perform the same diagnostics as in step 3.
7. 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.
8. Decelerate. This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.

 

thanks for the helpful info :thumbs:

 

Well, duh! Doesn't everybody know that :crazy: :crazy: :crazy: :crazy:

 

Oh, yeah there’s more :lol: :lol: :lol:
#7. Fat chance completing this one in Atlanta traffic, they ll run you re **** over at 55mph. Catalyst monitor diagnostics still had the red X in EFILive, but it passed the inspection anyway. :hurray: :party: