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Discussion Starter #1
I have a 94.5 f250 7.3 powerstroke, 5 sp , 4x4 - and the computer does not seem to produce OBDII codes. I've read / been told that there were changes to the computers used 'after' 94.5 models. I want to test injector issues and want to understand my options re: computer and codes. Questions:

- Will a computer from 1995 or after solve my code problem?

- How do I know which "code" on a replacement computer will work, and can it come from any 95 - 98 truck

- I know i'd need a '5 speed' computer, but does 4x4 vs 2x4 matter?

- Does 250 vs 350 vs 450 matter

- Will the wires / cable / install be 'plug and play' ? (how tough is swap)

- Are there any 'pitfalls' I should think about before potentially doing a swap?

- Would it be bad to buy a computer that parts store claims has be "chipped" (pros cons) ?

Thanks!
 

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my understand is that all of our OBS trucks were exempt from OBD II regulations. i have an OBDII connector but an OBD I computer. AE and a few other sources is where i have read this. I have 'heard' of people updating to OBDII but know nothing about it.

youll need a scanner that has some sort of 'Ford' package to read and run diags.
 

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Discussion Starter #3
Do you have a setup to pull your own codes?

Does it put out complete diagnostic test/info (right now i'm most interested in injector info)?
 

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i dont have a setup and havent tried one yet. this is all from what i have read. AE and some other scanners will do check, i dont recall which ones, hopefully someone will chime in. the cheap auto parts store ones wont.
 

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i'm fix'n to do the exact swap your talk'n bout'....i'll let you know how it comes out in a few hours.
 

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Discussion Starter #7
JH: thanks a lot for posting up, I appreciate it.

When you have time, I'd love to know:

- how important the computer code was when selecting used computer replacement (or does it just need to be 49 state model, for correct tranny type, and 96 or 97 year??

- how difficult swapping is (is it plug and play)?

- if you notice any performance differences (i.e. or just better diagnostic capabilities)

T H A N K S
 

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o.k....new computer is in. I can now read and clear obd 2 codes. the install was easy...took about thirty minutes. one screw holds the connector...two hold the computer in. you do need to take a few bolts out of the inner fender to gain enough clearence to pull the computer out. as long as you get a 96' or 97' computer with 49 state emission and correct for your trans you should be fine. i have heard that a computer for an auto trans will work in a manual but not the other way around (i have not verified this though). One final word of caution...i have a bad icp sensor (i think), the pre obd 2 computer apparently just worked around the problem...the new obd 2 computer will not let the tk run unless you clear the code from the previous run cycle. so if you do have some sort of issue like this...be prepared to fix the problem or have a code reader on hand.
 

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Discussion Starter #9
JH, thaks SO much for posting back up. A lot of times on boards you never hear back from the guy that gets his own issue successfully resolved. Thanks.

2 f/u questions if you don't mind:

- please post back up later after you've driven a bit, curious if performance is any different (i'm assuming it shouldn't be??

- forgot to clarify in my last post.... can the computer be from any f250/f350/f450 (given same tranny type)? (i have 250)

Thanks again for your time
 

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performance is comparable...possibly a bit more torque than before.
as far as i know f250,350...r the same...not sure about 450, but it should be.
 

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Discussion Starter #11
NEW questions - did computer swap

OK, I ordered and received a computer from a 97 manual to put in my 94.5 manual.

- install/swap was quick and pretty easy (note: there is a small bolt holding connecter into computer - plug won't come out if you don't see/remove)

- Truck started back up and seem to run fine, same as before

- Tried to pull codes both with a cheap home type OBD2 scanner and also at a shop with a pro type snap on scanner, both reported ERROR / NO READING :(

Looking for advice, here are 2 questions:

1) when pro scanner asks for YEAR and VIN# info what should you enter (i.e. info off of new computer (97) or actual info of truck (94.5)

2) Any suggestions as to how to 'test' if computer is putting out proper OBD2 data now after the swap?
 

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be sure to check all your fuses first...underhood and in the cab.
 

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Discussion Starter #13
JH: thanks for the suggestion, I will check the fuses.

Once I confirm fuses, do you know what I should enter for year/VIN (i.e. actual truck info, or that of the the 'new' computer)?

thanks.
 

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i think i would use the info that matched the computer you installed...technically the computer thinks it's controling a 97' model truck. just my 2 cents worth.
 
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