Switched o2 sensors, gas mileage took a dive
08-16-2010, 11:14 PM
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Switched o2 sensors, gas mileage took a dive So I got my long tubes on and I installed the o2 sensors, would it cause problems if I extended the original rear o2 sensors and used them for the front o2 sensors on my long tubes? My gas mileage took a major ****, I read it would go down slightly with the EGR delete(AIR deleted too but that doesnt have anything to do with MPG), but I don't think the EGR delete cause such a drop in mileage. Is is possible that the o2 sensors have to get adjusted with the swap of everything, and after they adjust my A/F will getstraightened out and itll run less rich and mileage will go up? The exhuast smells real raw or is that because my cats are gone?
08-17-2010, 01:09 AM
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The rear O2s are just to make sure your cats are working. They are not made to tell whether the engine is running rich/lean. If you dont have ANY front O2s plugged in then the car is prob just running as rich as it possibly can due to no input from the sensors. If you put the front O2 sensors back in and either put sims in the rear or tune them out (or even just leave them be if you dont mind the little CEL light on) I guarantee you youll run 100x better.
08-17-2010, 01:34 AM
#3
Get a tune. That will help a lot.
As Drop said though, the rear o2's are just to be sure the cats are doing their job. Unless you swap out the pins on the PCM, swapping out the front and rear o2 sensors won't help at all.
Your car will do some minor computer adjustments to try and even out the new stuff on the car, but it can only do so much, the rest needs to be accounted for in a good tune. Your A/F is probably off by a decent bit now.
As Drop said though, the rear o2's are just to be sure the cats are doing their job. Unless you swap out the pins on the PCM, swapping out the front and rear o2 sensors won't help at all.
Your car will do some minor computer adjustments to try and even out the new stuff on the car, but it can only do so much, the rest needs to be accounted for in a good tune. Your A/F is probably off by a decent bit now.
08-17-2010, 09:08 AM
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Yes, it will smell funky without the cats. Ahhh, the good ol smell from the 70's lol
Anytime you make a major change to the engine, exhaust, etc it needs to re learn the proper way to run. Think of going from barefoot to logging boots, you have to relearn the best way to walk.
Anytime you make a major change to the engine, exhaust, etc it needs to re learn the proper way to run. Think of going from barefoot to logging boots, you have to relearn the best way to walk.
08-17-2010, 04:00 PM
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Thanks guys, just to clarify front o2 sensors were always in I just think I extended the rear o2's and put them in the front and didn't know if it would affect anything. Seems to be running alright now, can this all be improved by a mail order tune of my PCM or will it not be fixed at all unless I get a dyno tune, because thats a lot more expensive.
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08-18-2010, 05:49 AM
#8
The rear and front o2's are the same part number so you shouldnt have an issue with the sensors as long as you have them plugged into the fron harness. Now when you say u extended them does that mean u cut and spliced the wires on the sensor? If so its entirely possible they arent making a good connection causing the car to run rich, the wires on o2 sensor were never made to be spliced. If you did splice them I recommend u go and get new sensors and use extensions or buy ones from a corvette which are already long enough befor you try to diagnose it any further
Dan-
Dan-
