Boss 302 5.0 tough to start, very lean.

Boaisy said:

I think I know of what car it is, or at least I saw it online a few weeks ago. By the pictures I saw of the engine, it was stripped down to just the long block, no intake. I believe it was an auction unit. Looked a little rough.

EDIT: kinda tree'd.

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http://www.s197forum.com/forum/showthread.php?t=127812

This was the thread on the car.

deebo05 said:

was the car flashed back to the as built stock boss file?

if not then its most likely the tune is still setup for the Paxton and will run lean. because of the maf.

loading the canned sct files just modifies whats on the ecm,It doesn't overwrite.

I would start with a as built file or get a custom tune

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That would make sense and that would definitely be the problem. I was under the assumption that the canned SCT file would overwrite the old file, not modify the existing one. I suppose getting a tune from scratch would be the solution? I'll give that a go.

you could also get the dealer to flash it back to stock, here in Houston its 125 to 150 bucks. some locksmiths can do it also or a repair shop.

deebo05 said:

you could also get the dealer to flash it back to stock, here in Houston its 125 to 150 bucks. some locksmiths can do it also or a repair shop.

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I have another 14 GT with a similar issue, it runs much better but hesitates under light throttle, pulls fine at high rpm. I believe that one is a similar case since I bought it the same way. I'll run that one to the dealer tomorrow and see what they tell me. Both cars have headers on them, so a tune will probably need to be done afterwards anyway.

most of the time on the coyotes, not always, you really don't need a tune for headers..
the adaptive will compensate for the transport delay and the widebands will also compensate for fueling errors, up to a certain point, from the long tubes.

let us know how it goes.

deebo05 said:

most of the time on the coyotes, not always, you really don't need a tune for headers..
the adaptive will compensate for the transport delay and the widebands will also compensate for fueling errors, up to a certain point, from the long tubes.

let us know how it goes.

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That fixed it right up! I sent the 14 GT I've been having trouble with first, since I could drive that one there. As soon as that one got done, I immediately had the Boss towed over. They called, said it was done. Went over and drove it back to the lot. Runs fantastic! Thanks for all the help!

I learn shit every day on here.

fwiw, i had a bad o2 sensor and my wideband was pegged at 20 as well

weather man said:

I learn shit every day on here.

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Seriously. That's why I love this place and reading things about cars I don't own.

irishpwr46 said:

fwiw, i had a bad o2 sensor and my wideband was pegged at 20 as well

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My first thought was a bad o2 sensor, but the wideband reads even when the car is off so the readout was not stuck at 20.

nice, glad you got them going

hopefully it was cheaper than a tune and a xcal.

deebo05 said:

nice, glad you got them going

hopefully it was cheaper than a tune and a xcal.

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Thanks for the help. I'd probably still be fucking around with it if you didn't post here. I think the dealer charged $149 for reprogramming. Only problem is it still has LT headers and no cats, so it'll throw a check engine eventually. So I still may need the tune.

not a bad price.

stick some non foulers on the rear o2's, you will be good to go. they are cheap and all the emission monitors will still set.

This is why I would never buy a modded stang, unless it was done professionally with high quality parts. So if I put Kook's shorty headers on my Coyote it wouldn't need a tune? I'm planning on a Ford Racing canned tune since I want excellent driveability, not maximum power.

Who does that to a Boss?? Unbelievable...good thing you are saving it.