Bad Gasmilage
07-05-2007, 08:51 PM
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Bad Gasmilage When I bought my 2000 camaro z/28 I was getting 21-23 mpg. I checked it the other day and I was getting 13. I havent been drving any different. Whats up their are no new mods. Do you guys have any sugg. The guy at autozone said it could be an 02 sensor but would it make that big of a difference. Thanks-Chad M
07-05-2007, 10:24 PM
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Yes, an O2 sensor is what is deciding your AF ratio in closed loop. It can have a HUGE impact on your milage. How many miles do you have on the car? Check simple thing slike plugs, air cleaner, wires, basic tune up stuff. It doesn't take much to start loosing fuel economy.
07-07-2007, 12:31 AM
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Im going through the same thing, I dont mean to hijack your tread. I dont have a SES light but Ive cleaned my MAF, cleaned my k&n, changed my fuel filter, seafoamed her twice, and set my shift light to 2K and try to keep it off... next are the damn o2 sensors, the LS1's have 4 though! and theyre about $85 ea! Im wondering if I need to change all of them of just the rears?
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07-07-2007, 11:00 PM
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Originally Posted by SoCalZ28
Im going through the same thing, I dont mean to hijack your tread. I dont have a SES light but Ive cleaned my MAF, cleaned my k&n, changed my fuel filter, seafoamed her twice, and set my shift light to 2K and try to keep it off... next are the damn o2 sensors, the LS1's have 4 though! and theyre about $85 ea! Im wondering if I need to change all of them of just the rears?
the back two just tell you if the cats bad. the front decide the af ratio.I would do like it was said check a plug. An O2 that is not reading correct will not always throw a code if Its still within thresold but not right it will not throw a code .................gut your cats, reflash your computer and its still cheaper than new rear O2 sensors.
07-08-2007, 03:17 AM
#9
13mpg! Thats like a Honda Hybrid! I was getting 8mpg with my previous turbo set-up!
Someone mentioned that the O2's decided your air/fuel in CLOSED loop. When is that exactly? When the car is first starting up, after it has already been running awhile, during idle, or during cruise? Because according to my wideband my cruise A/F was dead set on 14.4-14.7 but my idle A/F was really messed up. I obviously had NO CATS with the turbo system, and I changed the plugs AND O2 sensors (rears deleted) and it didn't change anything.
This is really the wrong section for it but I'll entertain you guys anyway. With HPTuners MAF tune, we set the idle and cruise A/F for 14.7. As I stated, cruise was fine but idle would not set to 14.7. On a cold start, it would start up and read 14.7 for the first three to four seconds. Then over the next 30 seconds it would slowly drop in .1 to .2 increments and then finally bounce around between 10.0 to 11.8. Weird huh? It was like the computer knew to idle at 14.7 but something wouldn't let it. What I don't understand is that while I know that the idle was way rich, it shouldn't cut my mileage to half, right?. As a test I once filled it up, got straight onto the freeway doing 55mph in fifth for about 60miles not getting on it once! I got right off the freeway and put 5 gallons in it! -It still only got 12mpg! How do you make sense of that? By the way, STOCK cubes, and at the time, STOCK LS1 intake and STOCK 2000 LS1 cam! Same motor in sig.
Someone mentioned that the O2's decided your air/fuel in CLOSED loop. When is that exactly? When the car is first starting up, after it has already been running awhile, during idle, or during cruise? Because according to my wideband my cruise A/F was dead set on 14.4-14.7 but my idle A/F was really messed up. I obviously had NO CATS with the turbo system, and I changed the plugs AND O2 sensors (rears deleted) and it didn't change anything.
This is really the wrong section for it but I'll entertain you guys anyway. With HPTuners MAF tune, we set the idle and cruise A/F for 14.7. As I stated, cruise was fine but idle would not set to 14.7. On a cold start, it would start up and read 14.7 for the first three to four seconds. Then over the next 30 seconds it would slowly drop in .1 to .2 increments and then finally bounce around between 10.0 to 11.8. Weird huh? It was like the computer knew to idle at 14.7 but something wouldn't let it. What I don't understand is that while I know that the idle was way rich, it shouldn't cut my mileage to half, right?. As a test I once filled it up, got straight onto the freeway doing 55mph in fifth for about 60miles not getting on it once! I got right off the freeway and put 5 gallons in it! -It still only got 12mpg! How do you make sense of that? By the way, STOCK cubes, and at the time, STOCK LS1 intake and STOCK 2000 LS1 cam! Same motor in sig.
07-08-2007, 02:36 PM
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soudn like my car (by the way i have the same year as yours) when i first brought mine from Seattle. Get it a Tune up, made a huge differences. Spark plugs, 02 sensor, fuel filter, air filter. . check all that.