Hawk777th

Hey guys I just bought car and put a new cat converter on it as I high centerd the last one bout 1000 mi ago. The car is an LS1 with LS6 heads on it and tons of mods. The car failed for NOx 4.7 and it has to be 1.5max to pass. Also the HC is 1.8 and it need to be 1.2max. Im wondering if my octane is to low as my manuel says min 93 and all we can get in co is 91. Could I try and put some race gas in it to help octane. Any help would be appreciated! I hate to pull the tune (if it has one I dont know) and put it back to stock. CO is fine. I also need to get rid of my 195 thermostat as it was all I could find in town that fit in the housing of the water pump still trying to get a 160. Car has 26k. Dont think the car got to cold it only say for maybe 4-5 min and the guy reved it a couple times showing off lol.
http://img189.imageshack.us/i/002vwd.jpg/
http://img24.imageshack.us/i/003yxz.jpg/
http://img189.imageshack.us/i/005ske.jpg/

wssix99

iTrader: (5)

Was one of your mods removing the EGR system?

Unless your octane issue is causing a knock, I doubt it would be involved here. (The emissions systems should be able to compensate for any inefficient combustion.) Regardless, if you've spent a lot of money on your engine, you probably want to give it 93 octane. (which is matched to the engine compression) Your engine will be much happier that way.

fleetmgr

Don't change that thermostat until after you've passed emissions. It's got a 195 in it for that very purpose. Cooling the engine down cools the exhaust, and exhaust temp is what starts the cat working.

dragonrage

What kind of cat did you put on it? Give the exact model.

Hawk777th

Magnaflow XL650039. I think the previous owner may have removed the egr valve. Im not sure where it is located on the Ls1 could some one please show me a picture of where it would be. Also I know the 2nd O2 sensor has been removed behind the cat.

Hawk777th

Looks like its not a magnaflow but a Imco. Wonder if that cats a piece of crap.

DCsLS1

what year is the car? 01-02 didnt have egr but check to see if your AIR was deleted its the tubes comming off the top of the headers then go around the back of the engine and one tube is in the side of your lid. I doubt the octain is causing it to fail, does it have a big cam in it?

wssix99

iTrader: (5)

Your second O2 sensor tells you how well your CAT is performing. So, without it, you'll never know exactly how good it is or how good its working.

The EGR is a main tool in controlling NOX. I doubt anyone could pass a direct measurement test without this system. Maybe if you put a hotter thermostat on and warmed up the engine more for your test. Cool air + engine is great for performance but not emissions.

Hawk777th

Looks like the Imco looks like a 60 dollar cat so Im sure its a piece of junk. My muffler shop charged me 300 for it so I guess were gonna have a talk... Its a 2002 it doesnt have a big cam in it. It lopes a tiny bit so Im guessing it factory or very light. It does have the tubes coming off the headers for the air pump but I dont know where the actual pump is. Someone said lid whats the lid?
Heres pics of the tubes I see they go back into some kind of canister.
http://img24.imageshack.us/i/img0566m.jpg/
http://img24.imageshack.us/i/img0567p.jpg/

junkindatrunkmx6

iTrader: (1)

NOx are created from combustion chamber temperature exceeding 2500 degrees. You need to change out that thermostat.

junkindatrunkmx6

iTrader: (1)

If you removed your egr then your only hope is installing a COLDER thermostat. Since our cars are computer controlled we can't just richen the mixture a little or retard the timing a little.

DCsLS1

there is no egr on a 2002!!!
your air pump is hidden below where the fuse boxes are just behind where your headlights are you have to access it through the trap door from the bottom. The lid is cover over where your air filter is.

DCsLS1

yes those are the AIR tubes if you follow the tubes they go into a valve on the back of your manifold and follow the tube that comes out it goes to your AIR pump where i said before then after the pump it goes into your lid. But it looks like that was not deleted so thats not your problem.

wssix99

iTrader: (5)

Correct - sorry - experiencing a brain fart.

junkindatrunkmx6

iTrader: (1)

Your secondary air only works on cold starts. Once your o2s heat up you go into closed loop... So it doesn't matter whether you have that or not. All it does is add air to cleanup hc's and co's when your car is in open loop. Your car should be in closed loop during testing. If its not then that is your problem... Do you have access to a scanner?

jimmyblue

iTrader: (11)

NOx + HC usually means over-lean to the point of
marginal misfire. You might want to see if this is a
cylinder imbalance problem, which would show up
as discrepant readings in the Misfire Current Cylinder
Mode 1-8 numbers. An injector imbalance can put
you in a situation where you have 3 fat comp'ing
one lean in a bank since the O2 sensor is averaged
to trim fuel. Then you get a "soup" of both rich and
lean pollutants.

You might pull out a little spark in the regions where
NOx is criticized, early spark can drive up peak cylinder
pressure / temperature. Especially since you've bumped
up compression. Just because the motor "likes" spark,
doesn't mean the Smog ***** share that opinion.

Might also elect to jimmy the AIR pump so it runs full
time (until test is over). That air can help give the cats
something to bust down the pollutants, with. And
perhaps dilute them a bit, at least at idle.

Hotter is better for everything but NOx, I would not go
to the 160 'stat because you may just push up HC. It
would be good to make sure fans are keeping the engine
coolant temp at thermostat temp and not much above,
though. As coolant temp swings, so does the tune and
that's not going to help any.

Hawk777th

Well the factory air pump works fine I just installed my 160 degree tstat and ran some of that mopar engine cleaner through it gonna try again. Would running race gas help at all? Also been told that a little E-85 would help it burn cleaner. How can I make the air pump run full time?

LS14EVR

iTrader: (3)

Back when we had to pass emissions tests in MI, I used to run about 3-5 cans of gas line antifreeze in the gas. I had a small pick up that was way over the limit. Got 4 cans of antifreeze, ran the crap out of her, brought it back 15 min later and the got a 0.0 ppm reading. The tech's jaw was on the floor and couldn't figure out what I did.

fleetmgr

Higher octane fuel won't help your emissions readings. All it does is prevent detonation.

dragonrage

Awesome tip; I'll keep it in mind if I'm ever in that situation.