No cat and running extreamly rich
This is a discussion on No cat and running extreamly rich within the LT1 forums, part of the Vehicle Specific category; I honestly don't think they tuned it right then. A tune for LT's and even a cat delete should put ...
12-29-2006, 01:58 PM #41
I honestly don't think they tuned it right then. A tune for LT's and even a cat delete should put the A/F right at its proper stoichiometric values. They can tune cams properly, then bolt-ons should be cake.
(BlackZ-LT1) Nice hood, by the way. I've been looking into getting that same one for a year now, but I have to save for other shit. Where did you get yours from? I can only find a few places that sell it. But I'm thinking of painting the center cowl and insert a metallic silver and the rest of the hood black. I think that would look kickass. What was the name of your hood? I know it goes by a couple names; big block hood, Z-Rock hood, predator hood...etc.
12-29-2006, 02:16 PM #42
12-29-2006, 02:38 PM #43
I read online that a clogged up air filter can cause your engine to run rich.
Also, if you removed the EGR, you might have problems. EGR = Exhaust Gas Recirculation.
There are tubes on the factory passenger manifold that attached to the intake manifold on the back.. I know because I removed them from back in the day when I did my head gasket. If your new headers dont have that same tubes (EGR?) then your system is definately not running like it was designed from the factory. Cant you run a header and leave the EGR intact and all other systems? Why remove the catalyst anyways? crazy.
Also I think leaving the O2 sensor at the same distance from the head is optimal.
but one thing I think is normal if the exhaust smells slightly richer after a cat deletion. Not a lot but maybe very slightly richer. Reason is not that removing the cat makes the engine run richer, but actually, the engine already ran that way. Its just that due to the temperature of the cat, it can burn off some access fuel if it is installed. But the engine was already running that rich to begin with, you just never noticed it until the cat was removed.. Now again, I think its a very small amount.. If you're getting bad gass mileage, like less than 18 in town, I'd say you have a problem.
Last edited by Chad97z; 12-29-2006 at 02:55 PM.
12-29-2006, 02:53 PM #44
Speaking of EGR, I just got my EGR block-off plates in the mail today. My EGR tube didn't line up right with my LT's, so I'm just going to block them all off. Except, I think I might just leave the EGR solenoid and block off the other 2. Does anyone think that will cause a problem? I just don't want to fight trying to get the 2 bolts out of the solenoid, because it somewhat covers the back of the bolts, and it looks like I would have to use a boxed-end instead of socket, like the other one.
12-29-2006, 03:00 PM #45
I tried blocking off my EGR once with a bolt and it was ok while it idled and drove easy, but when I took off harder, the SES light came on. Doesnt hurt to try though..
EGR is typically not employed at high loads because it would reduce peak power output, and it is not employed at idle (low-speed, zero load) because it would cause unstable combustion, resulting in rough idle.
Contrary to popular belief, a properly operating EGR actually increases the efficiency of gasoline engines via several mechanisms:
- Reduced throttling losses. The addition of inert exhaust gas into the intake system means that for a given power output, the throttle plate must be opened further, resulting in increased inlet manifold pressure and reduced throttling losses.
- Reduced heat rejection. Lowered peak combustion temperatures not only reduces NOx formation, it also reduces the loss of thermal energy to combustion chamber surfaces, leaving more available for conversion to mechanical work during the expansion stroke.
- Reduced chemical dissociation. The lower peak temperatures result in more of the released energy remaining as sensible energy near TDC, rather than being bound up (early in the expansion stroke) in the dissociation of combustion products. This effect is relatively minor compared to the first two.
12-29-2006, 03:36 PM #46
Well, I'm not removing it for 'performance' reasons or to see any gains. The EGR tube doesn't line up right with my headers and now I have a small exhaust leak and I just want to block it off to get rid of the annoying leak. If everything worked properly, I wouldn't bother with it, but I just want to plug it up. So I see nothing else I can do except this.
12-29-2006, 04:15 PM #47
are there any long tube headers that have the EGR and all street legal stuff that are hi po and work with all factory accessories? I want all my stuff to work and not leave anything hangn.. haha Whatever happened to those FLP headers that people were yipping about last year?
12-29-2006, 04:32 PM #48
There are plenty of longtube headers out there that come equipped with the emissions stuff. My mechanic told me, after I installed them, that I could have done away with the EGR and AIR crap and he would still pass me. I was like, damn, I wish he would have told me earlier.
12-29-2006, 05:07 PM #49
well, the air pump is just used to heat the cat faster at warm up only. Then it shuts off. So I believe it. And really the EGR doesn't work under heavy load, but it will help your gas mileage all the other times. So, I dont think your missing much.
01-02-2007, 08:12 AM #50
01-02-2007, 06:18 PM #51
Nice looking car!
Its funny, because you have the rims I was looking at too. From what I could tell, your car is pretty much what I want my car to look like in the future. I got the rear blackouts, clearcorners, red STB, pacesetter LT's, K&N FIPK II, ...etc. You're just a few steps ahead of me. Don't have all the engine dress-up stuff, but I must say, I like your style.
01-04-2007, 11:08 AM #52
01-04-2007, 11:43 AM #53
Well, it looks like I am going to put everything on hold til after college. I got a lot of shit to save for right now and the car isn't one of them. I think the best I can do this spring for the Z are badly needed new tires (Nitto NT555R), rear brake pads (ceramic from autozone), and maybe the LM2 to replace the flowmaster that came with the car. Other than that, the car is done getting new goodies for awhile. Unless I win the lottery.
01-04-2007, 12:16 PM #54
01-04-2007, 12:40 PM #55
01-04-2007, 12:52 PM #56
01-04-2007, 01:24 PM #57
01-04-2007, 01:37 PM #58
01-04-2007, 01:52 PM #59
Wow! This page is really off topic!
01-04-2007, 04:18 PM #60
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