I just installed the Performance tune on my 2001 F150, 5.4L, with Auto trans. I had previously ran the 87 octane tune with no problems.

I filled up with BP/Amoco 93 octane, then installed Performance tune.

At WOT, the engine clatters like I have water in my Gas, and transmission is slipping when shifting into 3rd gear at WOT. I went back and installed stock program. I then re-installed the Performance tune. I made sure all trans settings were at Stock tune.

I have 64K miles on the truck. Do I have bad gas, or should I swap out my forward O2 sensors? I currently have a fresh air intake, and a SI/SO 2.5" exhaust with Dynomax Super Turbo muffler.

What about the trans? I haven't driven it since I re-tuned it. I will test drive in the morning.

Thanks for any input you may have.

R1968

 

amoco ultimate is of poor quality since bp bought them, if you have citgo or sunoco- you shouldn't experience any pinging- by the way seeing you have more than 50 k miles- install new o2 sensor-pk

 

I plan on pulling the O2 sensors, and inspect them, before changing them out.

I usually run Shell gas, 87 octane without any problems. I used to run Chevron, but no Chevron where I currently live. I have tried Citgo 87 octane prior to Tuner, and it didn't do well. Poor mileage, and lack of power in my F150 and Mustang GT.

The trans still makes a screeching sound when shifting from 2-3 at WOT. My current pressure settings are at ST (stock). I am going to set them up one level each shift point.

I am unsure know if it is trans slippage, or assy. belt slippage, with the nasty noise it is making. I am going to watch the Tach closer next test drive.

**Will the bad gas damage my engine with performance tune?

 

Also be aware that if you just filled up prior to installing the tune, there may still be 87 octane in the system. How empty was your tank when you topped off with 93 octane? I always took it till the light came on before topping off with high test, and then I always ran a 1/4 to a 1/2 a tank of 93 before switching to the performance tune, that way I was assured the engine was getting a full dose of 93 octane before changing the computer parameters to the high performance tune. Just a thought, that might help with the engine noise. Don't know what to say about the transmission noise as I've never experienced that before.

 

the noise is the stock belt chirping- put a goodyear belt on it- detonation will damge the topend of the engine- how much 87 was in the tank prior to fillup of 93?-phil

 

I topped off w/ 21 gallons of 93 octane. The noise isn't as bad today. I have 60 miles on it since fill up, about 1/8 tank used. I will top off again with 93 octane.

My belt is Mighty Brand. I will swap it out with a Goodyear belt.

Thanks for the help. have a good week.

R1968

 

Hi Ranchero,

That is some God-awful 93 octane gas to cause detonation with the 1715's performance tuning - this is *precisely* why we tell people NOT to use BP/Amoco, as it is no longer the GREAT fuel that Amoco traditionally was before the BP buyout. Steer clear, it's no better than the off-brands & no-name fuels in many cases.

The shriek you are hearing is most likely NOT your transmission - it's the serpentine belt, because it's low grade. What happens is that you're hearing that noise only on a heavy-throttle upshift or downshift - (and maybe even if you're winding it out at full-throttle in the higher rpm ranges if the belt is *really* poor quality). The squeal during shifts is because you now have more power during the shift *and* a much quicker & tighter upshift as well - and that is something that even the stock factory serpentine belts are not good enough to handle. You need to install a Goodyear Gatorback belt *only* - don't waste time with any other belt, the Goodyear "Gatorback" belt is what you need, and will cure that problem. We can provide that for you if you like, or if you can't find it in stock locally.

We do not recommend "topping off" any tank of fuel - go ahead and run it down until the low fuel light first comes on, and *then* fill up any time you are changing from lower to higher octane, or when changing brands or source of fuel. When the low fuel light first comes on, you have 3.5 gallons left in the system in the 1997-2003 F-150's. That's when you change octane levels or brands of fuel, not before, as there will be too much dilution of the incoming fuel. Also, just FYI - never pump more gas after the pump has clicked off, something most of us used to do in older vehicles - you can't do that anymore as that will cause damage to the emissions systems over time. Also, do NOT use full-throttle with anything less than 1/4 tank of gas, as that can cause the sump to run dry and burn out the fuel pump, cause the motor to run lean before the system catches on, etc. - Just FYI...

You mention having problems with Citgo fuels there locally - and that can happen, but when it does, you can rest assured you aren't getting what we call "normal" Citgo gas. Chances are that station is most likely buying the cheapest gas from their local supplier to make more money, and/or sell gas cheaper, but you lose out. Citgo is on both BMW & Ford's "good gas" lists, and I run it in my 11-second Lightning running 18 PSI of boost with NO problems whatsoever - it's usually an excellent fuel. But if you are not getting a good result with your local Citgo, then you're absolutely right in not using it - just FYI on Citgo, it's usually a good fuel in most places.

Last - We suggest forget "inspecting" O2 sensors, you can't tell anything by that other than say, gross contamination from antifreeze, or gross carbon deposits which happens rarely - nor does the standard response time test tell you anything worthwhile unless the sensor is actually "broken" or "failed." It's a thermocouple, basically, so it deteriorates from the minute it's put into service. Your upstream O2 sensors are a 30K mile maintenance item, period. the automakers don't list them on their maint. schedules simply because if they told you to replace them before 80K miles, *they* would have to pay for it under the separate emissions warranty - so no automaker lists them. Sometimes you can push them to 50K miles in a normally aspirated engine, but I don't recommend that - you will get the best performance and fuel economy by installing fresh O2's every 30K miles. And make sure you use ONLY Bosch brand O2's - others will not work as well, your vehicle is designed for use with the Bosch O2's specifically - no matter what anyone else says. That's what they come with from the factory, and in this case it's actually the best & preferable part to use, just don't buy them from a dealership - instead, get Bosch upstream (also called "front") O2 sensors at your local auto parts store like an Auto Zone, where you can get them for about $50 each, instead of $80-$100 each at a dealership parts counter. The 2 downstream O2 sensors (the ones AFTER the catalytic converters on each side of the exhaust before it "Y's" down into a single exhaust) do not need to be replaced, as they do not provide A/F ratio feedback - the downstream (or "rear") O2's are there to check for catalytic converter presence & function only, so they can stay until they actually fail, or 100K miles, whichever comes first.

Hope that info helps & good luck!

 

Hi Ranchero,

That is some God-awful 93 octane gas to cause detonation with the 1715's performance tuning - this is *precisely* why we tell people NOT to use BP/Amoco, as it is no longer the GREAT fuel that Amoco traditionally was before the BP buyout. Steer clear, it's no better than the off-brands & no-name fuels in many cases.

The shriek you are hearing is most likely NOT your transmission - it's the serpentine belt, because it's low grade. What happens is that you're hearing that noise only on a heavy-throttle upshift or downshift - (and maybe even if you're winding it out at full-throttle in the higher rpm ranges if the belt is *really* poor quality). The squeal during shifts is because you now have more power during the shift *and* a much quicker & tighter upshift as well - and that is something that even the stock factory serpentine belts are not good enough to handle. You need to install a Goodyear Gatorback belt *only* - don't waste time with any other belt, the Goodyear "Gatorback" belt is what you need, and will cure that problem. We can provide that for you if you like, or if you can't find it in stock locally.

We do not recommend "topping off" any tank of fuel - go ahead and run it down until the low fuel light first comes on, and *then* fill up any time you are changing from lower to higher octane, or when changing brands or source of fuel. When the low fuel light first comes on, you have 3.5 gallons left in the system in the 1997-2003 F-150's. That's when you change octane levels or brands of fuel, not before, as there will be too much dilution of the incoming fuel. Also, just FYI - never pump more gas after the pump has clicked off, something most of us used to do in older vehicles - you can't do that anymore as that will cause damage to the emissions systems over time. Also, do NOT use full-throttle with anything less than 1/4 tank of gas, as that can cause the sump to run dry and burn out the fuel pump, cause the motor to run lean before the system catches on, etc. - Just FYI...

You mention having problems with Citgo fuels there locally - and that can happen, but when it does, you can rest assured you aren't getting what we call "normal" Citgo gas. Chances are that station is most likely buying the cheapest gas from their local supplier to make more money, and/or sell gas cheaper, but you lose out. Citgo is on both BMW & Ford's "good gas" lists, and I run it in my 11-second Lightning running 18 PSI of boost with NO problems whatsoever - it's usually an excellent fuel. But if you are not getting a good result with your local Citgo, then you're absolutely right in not using it - just FYI on Citgo, it's usually a good fuel in most places.

Last - We suggest forget "inspecting" O2 sensors, you can't tell anything by that other than say, gross contamination from antifreeze, or gross carbon deposits which happens rarely - nor does the standard response time test tell you anything worthwhile unless the sensor is actually "broken" or "failed," Look, it's very simple - it's a thermocouple, basically, so it deteriorates from the minute it's put into service. Your upstream O2 sensors are a 30K mile maintenance item, period. the automakers don't list them on their maint. schedules simply because if they told you to replace them before 80K miles, *they* would have to pay for it under the separate emissions warranty - so no automaker lists them. Sometimes you can push them to 50K miles in a normally aspirated engine, but I don't recommend that - you will get the best performance and fuel economy by installing fresh O2's every 30K miles. And make sure you use ONLY Bosch brand O2's - others will not work as well, your vehicle is designed for use with the Bosch O2's specifically - no matter what anyone else says. That's what they come with from the factory, and in this case it's actually the best & preferable part to use, just don't buy them from a dealership - instead, get Bosch upstream (also called "front") O2 sensors at your local auto parts store like an Auto Zone, where you can get them for about $50 each, instead of $80-$100 each at a dealership parts counter. The 2 downstream O2 sensors (the ones AFTER the catalytic converters on each side of the exhaust before it "Y's" down into a single exhaust) do not need to be replaced, as they do not provide A/F ratio feedback - the downstream (or "rear") O2's are there to check for catalytic converter presence & function only, so they can stay until they actually fail, or 100K miles, whichever comes first.

Hope that info helps & good luck!