Gas mileage questions
03-23-2006, 06:05 PM
#1
Gas mileage questions Hey guys, let me pick everybody's brains for a minute.
My gas mileage has been sucking for a while now. I'm sure that it's a combination of several things.
1) My trip to work is only 4.5 miles, and the engine barely has time to warm up to operating temperature.
2) My 4000 stall.
3) My old 02's
4) My Hypertech 160 Thermostat
I'm wondering several things...
Is there a way to know if the O2's are dying before they throw a code? It seems that the car is running really rich, like it's staying in closed loop. Could it be the IAT messing up? Doesn't it read really cold if it's not working right? I haven't thrown any code lights yet, BTW.
Is there a way to tell if the car is going into open loop without something to scan the PCM while driving?
Should I just go back to a 180 thermo to get the car warmed up better and adjust my fan settings accordingly?
Does a SERVICE VEHICLE light make the car stay in closed loop? I took the air bags out, and now of course, I have the constant SERVICE VEHICLE light.
Any help or insight would be greatly appreciated, I want to get my mileage back up reasonably with the price of gas right now. For an idea of how much gas the car is using, my tank is almost at the half mark, and I've only gone 74 miles.
My gas mileage has been sucking for a while now. I'm sure that it's a combination of several things.
1) My trip to work is only 4.5 miles, and the engine barely has time to warm up to operating temperature.
2) My 4000 stall.
3) My old 02's
4) My Hypertech 160 Thermostat
I'm wondering several things...
Is there a way to know if the O2's are dying before they throw a code? It seems that the car is running really rich, like it's staying in closed loop. Could it be the IAT messing up? Doesn't it read really cold if it's not working right? I haven't thrown any code lights yet, BTW.
Is there a way to tell if the car is going into open loop without something to scan the PCM while driving?
Should I just go back to a 180 thermo to get the car warmed up better and adjust my fan settings accordingly?
Does a SERVICE VEHICLE light make the car stay in closed loop? I took the air bags out, and now of course, I have the constant SERVICE VEHICLE light.
Any help or insight would be greatly appreciated, I want to get my mileage back up reasonably with the price of gas right now. For an idea of how much gas the car is using, my tank is almost at the half mark, and I've only gone 74 miles.
03-23-2006, 06:26 PM
#2
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Everything you mentioned will effect mileage. Sometimes you've got to choose what you want, but your mileage does seem excessive. Maybe others can come on and help you with this problem.
As far as the Service Vehicle light goes, removing the airbags will trip that, but usually only as a failsafe if you broke out the Airbag L.E.D. (ask me how I know, damned SH!TTY plastic steering wheels!). If you did not destroy the Airbag LED you could plug some 5 ohm resistors into the SIR circuit and trick the system into thinking the bags are still in there. I forgot the procedure, do a search on Airbag light/removal, etc.
As far as the Service Vehicle light goes, removing the airbags will trip that, but usually only as a failsafe if you broke out the Airbag L.E.D. (ask me how I know, damned SH!TTY plastic steering wheels!). If you did not destroy the Airbag LED you could plug some 5 ohm resistors into the SIR circuit and trick the system into thinking the bags are still in there. I forgot the procedure, do a search on Airbag light/removal, etc.
03-23-2006, 08:38 PM
#4
it is mostly the stall i would say i get about 190 with my old intake set up (FTRA), maybe i will get a little better with my new one 
, this is nothing but city driving though and only about 4 miles at a time like you said also, plus my stall is a little smaller, would keep the thermo in it really only helps like 10 degrees anyways
, this is nothing but city driving though and only about 4 miles at a time like you said also, plus my stall is a little smaller, would keep the thermo in it really only helps like 10 degrees anyways 
03-24-2006, 01:20 PM
#7
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Originally Posted by Grimes
If you get the rear o2s for a 2002 vette (bosch p/n 13111) , they have higher wattage heaters in them and longer wires. good for longtubes.
Last edited by WILWAXU; 03-28-2006 at 07:10 AM.