Need HELP with 99 chevy silverado 1500 (EGR)

Ok here is my problem i have a 99 Chevy Silverado LS 1500 5.3L. and i am having problems with egr codes coming up. I have been getting the P0405 EGR Sensor low circuit, i was told that my EGR was bad so i replaced it. ran fine for around 1-2 months and than the code came back on, talked with the guys where i bought it and they said that it could of been a faulty EGR so they replaced it. K so thats 2. 1-2 months down the road again same thing code pops up, talked with them replaced it again, number 3 so it did it again this time when i talked to them again they talked me in on getting the one better than the one i was using before and to buy a gasket with a screen. so thats #4. now today the code pops up again, havent talked to the store guys yet, might try to find oput if other people might have an answer for me or help me out. this time codes P0405 came up and also P0404. oh and i should mention that i replaced the wiring plug also. Thanks Greg

Have you cleaned the EGR passages.

i did also replaced the bracket that the egr sits on and also the egr line tube un less there is something else i should be cleaning or replacing

With the key on, you should have at least .14 volts DC on the brown wire at the EGR valve connector. If you have at least .14 volts at connector then check at PCM to make sure it’s at least .14 volts. If you don’t have at least .14 volts at brown wire at EGR then check gray wire to make sure you have 5 volts. If you don’t have 5 volts on gray wire then make sure there’s 5 volts at PCM. If not make sure all your powers and grounds are good for PCM. If all powers and grounds are good and you still don’t have 5 volts on gray wire at PCM, then PCM bad.

where is the best place to get a PCM and what do the cost i think mine is bad

first of all . . .

Has anybody checked with a multimeter, if the EGR is even getting its signal . . . ?

Has anybody used the scan tool to activate the EGR, to check if the engine stalls out, or at least runs rough . . . ?

I think you may be getting a little ahead of yourself with the PCM, at this point

yea i had it at the chevy dealer and they did activate the egr, yes there is signal to the egr. but when my codes come on it doesnt run or idle ruff though thats whats get me

Sounds like your EGR passage is clogged

if the dealer activated the EGR with the scan tool, and it didn’t run rough, it sounds like the EGR passage needs to be snaked out

Because you said the EGR itself was replaced a few times already, so that probably isn’t your problem, at this point

are you talking about inside the engine cause i replaced the egr tube line

@ChevyGuy56537 Thanks for the update

I was talking about the tube, actually

The EGR, it’s at front of the intake manifold, yes?

And the tube goes from the exhaust manifold to the rear of the intake manifold, yes?

Anyways, when the dealership guys activated the EGR, what happened?

Did the engine stumble or stall out?

on that i am not sure

@ChevyGuy56537 I’d check with them, or maybe look at your paperwork, before condemning your control module

These two codes that have been posted are for EGR pintle position. No codes for EGR flow. Have you performed the tests that have been given? Don’t assume it’s a bad PCM. Could be a bad wire which is more likely, But you have to test. Don’t guess.