O2 sensor and engine light

[senmag]

I got a 2000 LS manual, 200000 Km, runs great but engine light is always on and failed emission test. Got the codes scanned and got: P0171, P0174 and P1409. The latter is not specified. Wondering if replacing sensors would take care of the problem.
Could it be caused by a vacuum air leak?
Any help is appreciated!

[shorod]

Welcome to the forum!

Which engine does your LS have?

P1409 is a manufacturer-specific code. P1409 - EGR Vacuum Regulator Solenoid Circuit Malfunction. Per the factory service manual, possible causes of this are:

• EGRVR circuit open
• VPWR open to EGRVR solenoid
• EGRVR circuit short to VPWR or GND
• Damaged EGRVR solenoid
• Damaged PCM

The EGR vacuum regulator solenoid resistance is from 26 to 40 ohms.

Fixing the cause of the P1409 could very well resolve your other two codes as well.

-Rod

[senmag]

Appreciate the informations. Thanks.
The engine is v6 3.0 l.
We'll keep you posted.

[senmag]

Some follow up on current repair (after a little break for holidays).
Had a IDS diagnosis done from the dealer. Pointed to the EGR solenoid, a vacuum leak on the PCV hose. Replaced those parts and gaskets for the intake manifold.
The engine light was off shortly, and back after 5km. And still failing the emission test.
Mileage is 230KM (about 160K miles).Should I consider a complete tune up.

[shorod]

Have you checked the current codes to see if they are still the same? If not, I'd suggest doing that.

-Rod

[senmag]

Better late than never! ( that's on my promise to keep you posted)
I end up going to the dealer. Replaced EGr and selonoid, 2 Pvr pipe: no more engine light but still failed the emission test.
Replaced the converter.
And voila! ( > $1000)

[shorod]

Interesting to note. Bummer that it was such an expensive ordeal. Thank you for the follow-up.

-Rod

[Terrance05]

I just received the same code P1409 after having the Elbow fixed. Where is the solenoid located and is it something hard to fix myself or should I take it back to my mechanic? I changed out the EGR valve, but of course that was right on top of the engine and easy to get to.