red97,

FYI, the down stream sensors are there to check the integrity of the catalytic converters and in no way influence the engine's performance. They compare the O2 levels after the cats to what the PCM thinks they should be. If they are not in spec then a code is set. The up stream sensors are what the PCM uses for engine calibration. So replacing down stream sensors without a code is a waste of $$$.

Regards

Jean Marc Chartier

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00 F-150 XLT SC Flairside 4x4 4.6 w/5spd 3.55LSD
Warn XD9000i, skid plates, Draw tite class III,
Rancho RSX Reflex shocks,
BFG 285/75 R16 MTs,
Borla Cat Back, Headman Headers,
Modified Air Cleaner Outlet Tube
and air box, Ported Throttle body,
Shortened MAF sensor tower,
K&N air filter,
Superchips





[This message has been edited by JMC (edited 01-07-2001).]

 

Thanks Mike T.

 

Hi billycouldride,

The use of these oxygenated (reformulated) fuels is the result of the Feeral air quality monitoring campaign, so they will be in use until each geographic area's air quality improves to the point that they reach "attainment", according to the Fed's air quality monitoring program. They divide each state into numerous geographic regions and then monitor air quality in each region, to identify exactly where air quality needs to be improved. When an area is not in "attainment", then the state has several options, but the easiest is to mandate teh use of reformulated fuels, so that is what they do. First it starts in Winter only, and if that doesn't improve air quality in that area enough, then they'll mandate the use of reformulated fuels year-round.

So it all gets down to the air quality in your region as to whether or not reformulated fuels are mandated.

One thing that was changed is the use of MTBE in California fuels, it was outlawed just recently.

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Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Performance Products F150Online Superchip ordering system: F150Online Superchip Ordering System
First National F-150 Online Rally Event Organizer

 

Hi red97,

As you go up in altitude, oxygen content in the atmosphere drops, as does octane demand to a certain extent, so most of the pump premiums in altitudes of 5000 ft. and more are in the 90-91 octane range. Usually the 91's are OK for the most part, but when you get down to 90 or so, you may or may not experience some detonation, so just listen closely for it and if you hear it, you can simply pull the Superchip until you get good fuel back in the tank.

We have a lot of customers in those areas, and they usually don't have a problem using the Superchip on their pump premiums, but every once in awhile we'll see it happen, especially if the fuel is reformulated and lower octane due to elevation as well.

So the most accurate answer is to wait and see if you actually get any detonation, otherwise, you can continue to use it.

------------------
Mike Troyer
Performance Products, Inc.
National Distributor of Superchips
(540) 862-9515
Email: mtroyer@compuserve.com
Performance Products F150Online Superchip ordering system: F150Online Superchip Ordering System
First National F-150 Online Rally Event Organizer

 

Well, right now I'm sitting at a little under a half a tank with 163 miles on the odometer. I am very happy with that. That would sit me, at the present rate, getting about 283 miles on this tank which would be about 14 mpg all in city driving with winter time temps. I can defenately live with that. FAR CRY from getting 8.

 

Well, just filled up. Ended up with 11 mpg. 201 miles and used 18.5 gallons. Only first tank since O2 sensor replacment and Superchip. I'm hoping that goes up on the next tank. It's also winter driving.