5.3 litre chev V8

That's the way it sounds to me too.

Somebody is using one of those cheap little $25 "scanners", is just guessing at his problem and is merely throwing a lot of parts at the truck in hopes of getting lucky enough to accidentally land on the problem. Trouble is, all this while, Arnie is spending hard earned cash on this guy's foolish guesswork.

He'll ever get it fixed this way. He needs to have someone looking at the truck that actually knows what he is doing and has the proper equipment to deal with it.

Code 034. Yeah, right,

Allan

As you undoubtedly know because you are in the business, those trouble codes are merely a diagnostic tool and are not necessarily a 'chiseled in stone' indicator of the actual problem.

A guy has to have a very through understanding of the systems involved and how they operate to properly find the problem. That trouble code usually will get you into the correct neighborhood of distress, but you have to use your head and know the lay of the land to properly diagnose these kinds of headaches.

Further, and if my old pee-brain is remembering right, it takes something on the order of 50 key starts for any given code to ‘naturally’ clear itself from memory after any one problem is resolved.

What this means, is that if the owner has been in the habit of taking his rig down to “Barney’s Bakery and part time Bitchin’ Truck Repair”, and ol’ Barn’ hasn’t got sense enough to scratch his pet goat’s rear, let alone, clear the ECM’s memory of past trouble codes after all his attempts at tryin’ to fix this guy, the situation could occur whereby that memory is loaded with a string of old codes, which are totally worthless and are just complicating the matter of the current difficulty.

Yeah, I really miss turnin’ wrenches, but just not all that much. :>)

Allan

Not to get off the subject here, but is Don still teaching the trannys at the Training Center up there in Minneapolis?

Boy! You talk about one sharp dude!

Have a good one,

Allan

If it doesn't turn the light out, at least you had a nice drive.

HTH

Mark

Boy, I don't wanna speak outta turn here or jump the gun, but something is wrong in Chebytown, to my way of thinking. Are you sure about that code? How sharp was the guy that was reading those codes for you?

I just don't think "Code 034" is a viable code.

The old straight OBD code of 34 would point at a MAP sensor, but that would have been in the older systems.

The newer emission evap codes should fall somewhere in the P0400 range and if indeed you are experiencing a fuel venting (dumping) type leak, it would probably be more on the order of a P0442 or a PO455, if my memory serves. If it is an actual electrical problem (like a vent solenoid) it would of course be a different code, but should still be up in that PO400 number string.

Also, just to kick this around a little, the GMs don’t have near the problems with evap systems that the Ford models do.

Maybe this young GM lad that has been dropping in on this thread can give you a better answer than I, as I am going totally by memory here; but, it sure doesn't sound right to my mind.

Hope ya get 'er going,

Allan

Generally, it does NOT indicate the actual demise of the engine is imminent. (Such as an oil pressure or temperature light)

Check your gauges, and if engine temperature and oil pressure are "normal", don't sweat the light too much! (At least if you're not on the way to a "smog test".

Some of the newer vehicles are really touchy with what it takes to set off the light (to meet clean air regs.), and despite the best efforts at the dealer to lighten your wallet, the light will still come on from time to time.

Now I gave you 3 options. Hope one works for you.

Mark

Mark