EGR Valve Questions And Answers

Buick Century EGR Code
You can hear the fuel pump come on there's gas at the shrader valve where you put PSI gauge on the tree. Changed the gas filter. Took it got it scanned EGR code and (CMP) Sensor code came up.

Problem on my 2001 Pontiac Grand Prix
check engine light OBD scan code p1404 was pulled. Replaced the EGR valve, but code came back. Any ideas much appreciated on how to fix this problem.

Oldsmobile Aurora V8 4.0 Liter
The "service engine soon" light is on. Sometimes it turns off but only for about 5 miles and then comes on again. I used a computer reader and I found 4 codes :P0404 P0300 P1645 and P0404.

Chevy Monte Carlo Check Engine Light
I WOULD LIKE TO KNOW WHAT Exactly DOES CODES P0128 P0440 P1440 MEANS.

The EGR system is used on the engine to lower the oxides of nitrogen- (NOx) emissions levels caused by high combustion temperatures in the cylinders. It does this by decreasing the combustion chamber temperature. LEARN MORE

Question: chevy 2500 van 1999 p1404 code and check engine light comes on. Any ideas.
 Answer: Most likely a bad EGR valve or carbon build-up in the passages in the intake manifold.

How do I troubleshoot po410 problem.
 Code P0410 is not an EGR problem. That code is for the secondary air emissions system.

What does i have to do to fix my check engine light codes for p0174, p0171 and p0139 on my suzuki verona?
 Check for vacuum leaks and the operation of the EGR valve.