I have a modified corvette (425 hp without the juice) and I am concerned it passing emission testing here in Connecticut.

Should I be concerned and can anyone recommend an emissions friendly place to go.

777

 

I live in Houston, TX. and we have pretty strict emissions here. I had an 03 Mach 1 with cams and full bolt ons. Passed inspection with two "not ready" systems(evap and egr were turned off). They said that as long as the check engine light is not on and that you have converters, and the car has had proper drive cycles since the last check engine light, emissions should be no prob(and i believe at the time that the converters were hollowed out). I think they said the max here was two not ready systems and still passable. Hope this helps.

 

I've passed emissions twice in Illinois with the mods listed below. I'm not sure how they test cars in other states, but they just plug them into a computer here. Good luck!

 

I've passed with hy h/c/headers/hi-flo cats/cutouts/etc. in two states - GA an IN. They used the OBD II plug in both cases so you need to be concerned with how many Not Ready indicators you get if this is how they test in CT. When I brought it here, I had to do a GM driving cycle to get the PCM to read only two Not Ready's because I had to flash a new tune into my PCM on the trip up due to a MAF issue.

If you have someone around you with EFI Live tuning software, they can run the emissions test to tell you ahead of time if you'll pass. That's haow I figured I needed the driving cycle to pass my last test. I drove the cycle on the way to the test station, stopped and checked it before driving into the station and passed with no problem.

 

Thax for the replies.

777

 

Here's the GM OBDII Driving Cycle Instructions:

General Motors' OBD-II driving cycle

• 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.

• 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 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.

• 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.

 

Anyone know if you can pass emissions in MA with a swap done? How would that work for them?