Probably.

If you only feel it at idle, it is probably just a lean-burn-miss... at idle, the PCM will lean out the mixture pretty good, and sometimes, you get a bit of a miss.... especially in park, or neutral.

 

You could use a timing light and run through each of the wires and see which one(s) is/are misfiring, and go from there......

The blinky blinky should show even the slightest misfire....

 

When I hit 45 I feel a slite shake nomatter if od is on or off .I can't hear anything.Nobody else seems to notice it.It happened after the plenum fix&egr delete.did find a exhaust leak today when I gutted the cat I cut A u shape&welded it back up looks like its leaking from there but I had the shake before that.Also my idler pulley is shaking.
How do I check it with a timing light.Also I thought it was strange when I did the plenum when I went to relive fuel pressure from the rail nothing came out.

 

Connect the appropriate cables to the battery, then connect the sensor do-dad to each spark plug wire, individually, and there's a light at the end that flashes each time spark shoots down the wire. You'll be able to see regular and irregular spark patterns this way, and on which spark plug/wire....

Just an example of a timing light:



Basic ones are cheap at auto parts stores, I bought a cheapo for $40 a few years ago from O'Reilly's

 

Thanks&so were clear if there's a miss@45 it'll be pretty violent as if the whole things gonna shake apart...that would make alot of sense Because when I did the egr delete I left the block off plates off by accident before my test drive&when I hit 45 it felt like the truck was gonna shake every nut&bolt loose

 

Exactly.

When I did my plenum, I crossed two plug wires...... when I got to 45 mph, and the truck shifted to O/D..... holy crap, I had to hang on for dear life. Makes death wobble seem like a massage chair.....

 

Its not shaking like it did when I had that issue when I deleted egr but man it still has a slight shake@45 it is driving me nuts to the point I almost wanna sell her I have no idea what to do next

 

Does this shake occur regardless of whether you're accelerating, cruising, or decelerating? If so, look for unbalanced rotating parts or bent suspension components. Any engine miss you'd detect as a shaking with overdrive disengaged at that speed would almost certainly give you a pronounced audible miss at other times. I'd be looking at drive shafts, u-joints, and so on, things whose rotational velocity is directly proportional to wheel speed, first.

 

Sorry so long getting back...&yes it occurs if I'm cursing or on the pedal,also I notice it with od ON never really drive with it off.

 

In that case, next time you're mindful of it you should switch the overdrive off to see if the symptom changes. I have a gut feeling that it won't, but it's usually a good idea to do the free tests that are available to confirm or deny hunches and SWAGs.