GlockLT4

Seeing that my inspection is out and has been for a while, time to start thinking about getting it inspected. Right now no codes are showing. Does anyone know if this is good enough for inspection, or does it look back into the history of the computer? This is in Texas.

This is an LT4, so it's running OBDII, no emissions dyno test....

Modifications that may cause failure:

1) long tubes (removed AIR system)
2) rear O2 simulators (i think one isn't working)
3) LT4 HOT cam
4) Custom 3" catback (high flow cats, H pipe, Magnaflow mufflers)

Anyone else attempted to get a '96 car inspected with these mods? The car runs fine now that I fixed an issue with wires that was causing a miss, so emissions should be fine (except the AIR system exhaust recirculation).

A while back I had a buddy with LT1/LT4 Edit turn off a couple things, but I really can't remember now what it was (Rear O2's, and MAYBE the AIR system).

oldalaskaman

if it has to pass a visual......it wont.

ttpfi

No visual in Texas. As long as you have cats, your fine.

STL94LT1

A blast from the past, welcome back Curtis!!

PLRX

Do they connect "the sniffer" to the mufflers?

Steve85

I thought this was going to be one of those threads from 2003 that got dragged up again. Maybe Scorp has the answer

Good luck with the inspection, IIRC, places that rely on the OBDII just check for codes, but some of those have a visual as well to see that the equipment is present and appears to be in working order.

In terms of history, to some degree, yes. They will look to make sure that the car has been driven sufficiently to detect a failure that was recently cleared. As we know, not every code is set immediately, it often takes a reccurence of several drive cycles for the PCM to determine there is problem. This "history" check is to prevent getting the code cleared at the service shop across the street and driving up with no codes to pass. Whether they can detect certain things being "shut off" I don't know. I would venture guess they can't see what is shut off, as the actual programming in every mfr is diff't. i.e. you can't tune a GM PCM using VWs VAGCOM.

How long was the car down?

GlockLT4

yo yo!! Yeah, had to go and get MARRIED .. now i'm starting to settle back in and get more time to drive the vette. And boating season is over too, woohoo!

GlockLT4

not on '96+, unless there is some reason that their computer can't talk to your computer (like when i had an OBDI computer in my car so I could program it, rather than the stock OBDII).

GlockLT4

Haha, yeah - don't get nearly enough time on CF since I've been at this job (4.5years now!) - and certainly not like I did in college, ha.

I had my Tahoe done over the weekend and they didn't even pop the hood, so I think i should be ok on visual. I had this car passed once a while back at a firestone soon after getting the headers on and I think they looked under the hood more to just see what I had - didn't care for inspection.

Yeah, I agree with you on the history to prevent people from clearing codes and showing up. I remember when I did a bunch of OBDI programming that lots of the codes had to be set x many times within y many starts and had to occur for z many minutes/seconds at a time before a code would be thrown. One in particular that would be similar to this is misfires (i know you get a certain amount per some time frame, but can't remember specfics).

Soooo... yeah, if I can keep driving the car for a few more days and it hasn't thrown a code, then I may be safe. Just don't want to get stuck having it fail somewhere due to something I can't really fix (without detuning the car). Also don't want to take it to an "inspection" place every year that runs a few extra pennies . Hell (*knock on wood*), I haven't had it inspected so many of the past few years that the $40 savings are probably adding up to the cost of a 30/60+ day overdue inspection ticket that is $200 ish anyway!

Car has been running, just not inspected (exp. 4/08, whoops). Had some wire issues (just got them fixed up finally last weekend) that were preventing me from driving it much. Main factor has just been SOO freakin' busy with work, extra jobs on the side, wedding prep, and trying to save $ by not going out (which means less driving anyway). I don't drive her to work down I35 because i like having the car in one piece, and I don't even think it could make it down into the parking garage at work, ha. Ever since getting a boat I find myself driving it less too since weekends used to be when I drove it a lot. Add in no heater core and that reduces my driving season (yes, even for us Texans, ha). Excuses.. excuses . I'm working on it and trying to get her back to "legal" status!

96GS#007

The OBD II check looks for the SES light to be off, no codes to be set, and for emissions monitors (sometimes called flags) to be "set".

Rather than type a bunch of stuff, I pulled this off the TX Dept of Public Safety website (other states are similar):

"These monitors are like self checks of each emissions component (EGR, O2 sensor, etc) within the OBDII system. These non-continuous monitors are considered Ready until either DTC's have been cleared with a scan tool or if battery power has been disconnected, then the monitors will reset back to Not Ready.

In order to get the monitors set back to Ready, the vehicle must be driven through a drive cycle, which is a combination of city/highway driving for a set period of time. This drive cycle relearns the OBDII system and rechecks all of the emissions component's individual systems. As each system completes its own self test, the monitor will set back to Ready.

Effective October 15, 2008:

For vehicles year model 1996 – 2000, we allow two (2) non-continuous monitors to be Not Ready and still pass the test, but three (3) or more Not Ready's will cause the vehicle to fail.

There are three (3) continuous monitors that are always Ready: Misfire, Fuel System, and Comprehensive Components. If you look at your Vehicle Inspection Report (VIR), you will see the emissions monitors listed and their Ready/Not Ready status. If any of the non-continuous monitors say N/A (Not Available) or N/S (Not Supported), then there is no monitor for that system.

This information is illustrated in a "Ready or Not" poster displayed in all of the emissions testing stations as well as the Recognized Emissions Repair Facilities (RERF's)."

With your failed O2 sim (and/or the rear sensors disabled) and the AIR system disabled, you will have the Catalytic Converter, heated o2 sensors, and Secondary AIR monitors show as "not ready. You may also have the o2 sensor monitor show as not ready (although I seem to recall that on a '96, only the front sensors are checked such that it'll be fine). None the less, with three "Not Ready" flags you will fail the plug-in test.

Here is where it gets tricky. In some states, once you fail the plug-in test, you are forced to perform the sniffer test or wait ONE YEAR before trying the plug-in test again. This is the case in WA where I live and I found out the hard way :o. Rather than waiting a year, I messed around with my tuning and in one try got my 383 with AFR Eliminator heads, and a .62x/.62x lift / 230/236 cam to pass the sniffer.

Here is a link to the GM OBD II drive cycle.

Autotap can check the monitors. That way you'll know what to expect before you go to the emissions station.

JAKE

In Texas it varies by County, too.

When I live in Dallas County (Lancaster, sharing the City Limit boundary with the city of south Dallas) my 96 LT1 and my son's 96 LT1 had to be inspected for years. We used different inspection cites too.

In DeSoto: Beltline Road Care Repair Shop on Beltline half way between Polk and Hampton - south side of road and #2 Gas station on the south-east corner of Hampton and Pleasant Run Road (forgot what kind of gas they sell, LOL) Hit 'em up if you need to.

My mods are in my signature; his are similar - custom cam on 109 LSA, Dart heads but his has stock CID -. Both of ours have PCMFORLESS re-programming.

His has rear 02 by-passes and a Corsa CAT Back; mine has the stock 02s and stock exhaust. Can't help with the removed A.I.R. though. Prime the Pump, Make friends; buy him a Pepsi, etc.

Both passed year after year on the first test. No tail-pipe, but, yes, there is a visual which is suspect happens in all the counties.

I moved to Kempner (a couple hundred miles south) and had my 96 inspected last week. Not even a computer test - different county - just a visual, emergency brake, lights, etc. $14.95 "I love the color" LOL

Hope this helps.

Jake

BSenzina

A trick we used to do when I lived in Indiana was to pull the air cleaner and jump on the Interstate and run it hard for several miles....supposedly the extra air going thru helped with the emmisons for a while...We wnet straight to the test site after the run....air filter back in place of course.... We dont have them anymore in Florida.

GlockLT4

Yeah, i had found what you copied above about the 3 "not ready" statuses. AIR system will definitely do one, but not sure about the others. I remember that front O2's are the only ones that matter on the '96 OBDII as well. So I may actually be ok. I think I may have to find someone with a scanner to tell me (i don't think Autozone/Oreilly scanners will look at ready status like this - but not 100% sure).

GlockLT4

If i was having problems with emissions, then I'd do this, however I think the car is running fine. LT4 HOT cam doesn't have THAT much overlap that it's spewing gas out the back. The cats will help that anyway. And this kind of test would only happen if they couldn't read my computer anyway.

hgh pwr

I would do a search on wether you need the rear o2 sensors,because i remember some posts saying 94-95 don't use them and 96 uses them because its obd2,hope i am wrong.

GlockLT4

Ok. You may actually be right, because my previous car was '94 and that might be what I was thinking about. Thanks!

PLRX

heck, here in CA theyplug the ECM, connect the sniff to the car at 15 MPH and 25 MPH and test your fuel cap. Soon or later they'll start a liar detector on owners "Have you ever installed aftermarket parts and removed them for this inspection?"

btr85vette

I live in AZ, and I have collector car insurance for my 85. It let's me drive it to work a couple days a week, and the best part: NO EMISSIONS! The company, NCM, said there wasn't a year limitation. Might be a viable alternative.

GlockLT4

That's interesting. I might have to check with my insurance on this as well. Still only have 65k on her!!! At the rate of 20k miles in 8-9 years, surely that is enough to qualify for collector car status?

96GS#007

I ran mine initially without rear o2 sensors or sims. The monitors I mentioned above will not set. They are a '96 & up OBD II requirement.