So I have a 98 Dakota. I wanted to put a octane sensor on the fuel system to be able to adjust performance on the fly ( dual tanks the stock one with regular 87 and a small reserve with 110 race fuel and a switch or shutoff) is it possible to add a octane sensor? If I could, would the computer be able to adjust fuel curves and timing while running based off of that sensor? Or is there another way to do this?
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Welcome to the forum Austin.

Not with stock PCM. It's just not designed to do that. There is no input for any such sensor.

You may be able to find aftermarket tuners that can adjust the fuel/timing curves though.

 

No there's nothing in the stock ecu that will do what you're after. I would give you a wide array of different octanes on a tuner that would help you. It won't be on the fly switching though.

 

Well the PCM will self adjust for it but run the same or a little better. I used premium in my Dakota for years so the PCM got used to it and every time I used mid grade fuel it ran like crap. The PCM will adjust to the fuel grade but you must stay with that grade of fuel.

As to benefiting from it I say yes but most would say no.

 

These have flat top pistons that are prone to carbon build up so yea I can see where running premium fuel over time will allow it to run better. And I can see going back with low octane will show some troublesome functions after being on premium for a while. But the actual ecu has 1 timing table set. It adjusts timing based off engine temp and air temp. It doesn't adjust based off octane levels. There are no knock sensors to make it add/remove timing based off spark knock. The different octanes won't make it run different timing intervals. The only way to truly take advantage of different octane levels is with tuning so the timing is adjusted for the octane level.

 

Ok, its a v6 5speed so any extra power is always welcome. Any tips or ideas to acompliah this? On a budget of course.

 

I have a handful SCT 3200 models left in stock. you can check out my site

 

Ok, what type of bolt on parts are available for the 3.9 without breaking the bank that would compliment the tuner? Would 200hp be unreasonable for the 3.9?

 

electric fan mod and 1.7 rockers will free up a surprising amount. That's what I did. Sent you PM.