The EGR valve isn't causing your issue.

If you can't afford a rebuild, buy a junkyard unit, can be had for a lot less than 2k.

 

Yea you'd need to do little testing check it out figure out the cause of code,

Possible causes, poor continuity in EVP harness or connectors, intermittent open or short in EVP sensor or harness, damaged EVP sensor.

Do you believe you received a clean and accurate reply from the computer that time?

You stated The upshifts have gotten increasingly harsh,

Could you elaborate on how the trans acts in more detail, how it shift limited to only one or two of the upsifts or all forward gears effected equally but never slips etc etc.

Happen at a given speed and throttle input?

Simple quick test, if you disconnect the battery for a few minutes clear all codes, does the trans shift normally for a short time after doing so but then go back to harsh shifts again after drive cycle?

 

P to r is very rough. Shifting in d is followed by a huge clunk that actually shakes the whole truck. When driving 1st to 2nd is the worst, 2nd to 3rd is not smooth but much better than any other. As for 1st to 2nd it seems the worst as slow speed. Disconecting the battery makes no change . Tranny aslo never slips.

 

How's its idle speed? normal?

It shifts into every gear? would you describe it as it does shift but slamming into each gear and very hard when it does it? like it has a shift kit installed thats way overboard? shifts but the seat hits you in the backside near point of wiplash? Mushy sloppy shifts instead but does shift?

Does it wait to long to shift or shift too soon at any point? Hold gear too long rpms climb shifts at times have to let off the throttle for it to shift for example?

does it slip? as in the rpms climb but ground speed doesn't change etc?

Disconnecting the battery it wouldn't make any difference if its not generating error codes you're not seeing/that it isn't reporting (or just isn't the problem), if it did though for example that type reaction would provide a solid clue on condition of the trans itself / where the fault lies, electrical or mechanical.

 

Idles great, at about 800. Shifts into every gear even od. High rpm shifts seem to be slightly smoother. Tranny never slips. Never seems to shift prematurely or stay in gear too long without shifting. No mushy or sloppy shifts. 1st to 2nd is just jaringly hard

 

Possible its the trans but doesn't sound like it doesn't fit the norm for failed trans so to speak, leans heavy to trans control type issues.

If where my truck think my next move would be to pull the computer remove its cover and look it over for any signs of trouble go from there perhaps check solenoids.

Then it might come down to checking a few circuits if nothing just to eliminate a connection problem as the cause of its troubles.

Passing the self test if it is actually doing so suggests they are both good and the trans has problems, but not if the computer is suffering issues as in doesn't even know if its keister is drill, punched or bored.

 

mine did the very same thing, it was a broken sprag. Had to rebuild. Got a deal at $1500

 

Not so well versed in the electric side of things. So dont laugh... where exactly is the computer located. Sure I could have looked it up but figured someone could use a good laugh. Thanks again for all the responses. Just got back from driving it and it feels a lot better. Not great, just not so harsh from 1st to 2nd. Still really bad into park, reverse and drive.

 

Computer's down on the driver side firewall, look for the biggest electrical connector on there and that's it. Unbolt the connector, remove the retainer plate, slide the computer out toward the front of the truck. Might have to loosen the fender liner for clearance.

Also... did you think to check line pressure on the trans while it's acting up? It sounds like your EPC valve is pegging the line pressure. If that's the case, then either the valve failed or the computer is commanding high line pressure due to either something it sees as a problem or because it failed. Also a remote chance you could have the EPC signal wire shorted to ground but not likely.

 

How would I check the line pressure? Also where is the epc valve located? Is it replaceable? Thanks for the info.