EGR Valve error code

[Erik P]

Have 2001 suburban with the 5.3.
Mechanic has replaced EGR valve 3Xs. Error code specifies "replace EGR valve". Each time car runs fine for 4-6 weeks (500-1000 miles) and then service engine light comes on. Shortly thereafter the car will not idle correctly (under 1,000 rpm) and will die at stop. I think the EGR valves are getting clogged up with carbon. Car has 130,000 miles on it.

Suggestions please.

[777stickman]

1st suggestion is to provide the actual DTC code number, not just a description of it. I'm sure that some where in the trouble shooting chart it does say to replace the EGR. However that most likely comes after going thru 10-20 previous steps.

Again, we need the code number.

[Erik P]

Codes: P0404 and P1404.
Thanks for the reply.

[777stickman]

Originally Posted by Erik P

Codes: P0404 and P1404.
Thanks for the reply.

P0404 says "replace the EGR" at step #20. (Open Position Issue)
P1404 says "replace the EGR" at step #10. (Closed Position Issue)

Both of these codes can be caused by carbon build up as you mentioned.

Carbon build up in the EGR can be caused by a restricted exhaust system. Possibly a plugged CAT or muffler or??

Checking that would be my next step.

[j cAT]

Originally Posted by Erik P

Have 2001 suburban with the 5.3.
Mechanic has replaced EGR valve 3Xs. Error code specifies "replace EGR valve". Each time car runs fine for 4-6 weeks (500-1000 miles) and then service engine light comes on. Shortly thereafter the car will not idle correctly (under 1,000 rpm) and will die at stop. I think the EGR valves are getting clogged up with carbon. Car has 130,000 miles on it.

Suggestions please.

the 404 code means that the EGR valve is not with in 10% of its expected position. 1404 code means the valve is not in the closed position .

PCM disables the EGR when these errors occur.

inspection of the EGR for deposits is required as well as the wiring. bad wiring will cause errors also including the PCM connectors.

excessive oil consumption can cause these issues if the EGR has a deposit build up. I would also check the fuel trims to see if they are in the normal range along with the O2 sensors voltage readings with a tool that can show the graphing of the voltage swings over time.

broken exhaust manifold bolts can cause rich fuel mixtures .. / leaking exhaust etc..