I am currently going bonkers trying to get my car smogged.

I have a SC'd 383 with 42# injectors, mild cam, heads and forged pistons bringing down compression to 9.0:1. headers, etc.

So, you might think that it is so outa whack, it'll never pass. But actually, it has superb gases, on the dyno. It is ready to pass,...except that the PCM never completes some tests, of which California now mandates be interrorgated during its smog test. You not only get the sniffer up the butt-pipe, but the wheels are spinning and the OBDII is being interrorgated.

LT1 edit has been good, but I think GM and CARB are conspiring to inspect and weed-out.

My car can pass gas with the best of 'em. (so can I). But the tests need to run.

So....

I found that the car needs to run a "GM Drive Cycle" upto five times to run some of these tests. If you disconnect the battery, reset the PCM or anything of such, then the tests have to be rerun. I hereby assert.."THE TEST CANNOT BE RUN". It is constructed to fail.
1) Idle with Rear defroster/AC on for 3 mins. (okay, I can do that).
2) Accelerate at 50% throttle to 60MPH. (that's tough trying to keep the tires from spinning, but I can do it).
3) Hold 60 MPH for 3 mins. (Now you're assuming that there is a 3 mile stretch of unpopulated highway that I can put the car on cruise control without tapping the brakes or slowing down..pretty tough, but I can do that).
4) Decelerate from 60MPH to 20 MPH, but do not change gears, touch brake, throttle, or clutch. (Car will not slow to 20MPH in 6th, 5th, and tough for 4th).
5) Do this 5 more times.
6) Car is not legal to drive without license.
7) Cannot get license without smog check.
8) Cannot pass smog without driving it.
9) go to #6 and repeat.

 

I know. I put so few miles on my car ('97 wiht 18k miles) and I'm always doing some work on it or disconnecting the battery for winter storage that I don't think I have ever completed the cycle (I have AutoTap and check it occasionaly and it's not set as completed.)

Also I tried to run the cycles once and as you mentioned with traffic it is next to impossible to do so I gave up. Fortunately we don't smog check here yet.

 

I'm also in Cali with probably a little more radical set-up than yours but my car is 94 with OBD1 and I'm not in a smog enhanced area which is a relief. What gear do they make you put it in for the 60mph test? Could you leave it in 4th?

 

Good luck, I put several thousand miles on mine without resetting it before I swapped to obdi and mine would never relearn the blm's

 

what do you check in Autotap. It's a pain to find all the emissions monitors. Could someone send me their config file for autotap?

 

Ask for a temporary sticker for your car. It is a one month sticker that you can get for trying to register it. Then you are temporarily legal to drive it at least for DMV.

good luck

--Hugh

 

There is a flag set if the Drive Cycles have completed succesfully. You could look at this flag with AutoTap, at least with an older version, the last update I put on I wasn't able to find it.

 

Did you ever get a fix for this? I am going through the exact same problem.

I have a 383 LT1 with modified PCM, and the rear O2 sensors are disabled.

The codes that are failing are O2 Sensor; O2 Sensor Heater; EGR.

I have gone through the drive cycle as best as I could, not sure if I got it 100% as trying to complete some of those tasks is like an elephant trying to balance 5 plates spinning on a pole while riding a unicycle on a tightrope while someone shoots you with a BB Gun. Mathmatically possible, but just not sure how probable.

I'm wondering if because the PCM is progammed to not look for the rear O2 sensors, it's not generating the code. I'm just wondering what your case was before I spring for LT1-edit and reflash my PCM with a stock program.

-Keith

 

Bringing up an old thread, I know, but I have the same program.

Recently didn't pass smog, so I reprogrammed back to the stock tune...not waiting and waiting and waiting for I/M monitors to reset.

Anybody got a proven trick for this? I read the OBD2 steps that's floating around the internet and tried to follow it the closest I can. But I hear if you go above 60mph it cancels the test? I never got my monitors on yet.

In Cali..yeah sucks..so got the extension for 2 months. I just need to get these monitors set to re-test for smog...else selling this puppy as "As Is - you smog it".

Let me know if anyone's figured a good way to get the monitors set, please.

 

http://www.obdii.com/drivecycle.html ALSO depending on the state/local requirements only a certain number of diagnostics can be disabled otherwise the excessive disabled diagnostics will flag a not ready condition..