Help with P0401

[Immp]

Hello all,

New to the forum and not a great mechanic, but I am trying to fix a problem for an emissions check.

Car: 98 Camry 4 cyl

Prob: engine code P0401 (repeatedly)

Done so far:
Replaced EGR Vac Modulator
Cleaned EGR Valve
Cleaned Throttle Body
Replaced work vacuum lines

Lady at Autozone who is reading the check engine light says that I need to replace the EGR valve itself. Friend who is more mechanically inclined says it could be an O2 sensor.

Just trying to get it fixed enough to get an emissions. What can you guys tell me?

[Chris Crash]

VSV on the back of the engine. Those usually go first. I literally just did this and it's a ten minute swap. Make sure it's plugged in correctly though or it still wont work.

[Immp]

Is the EGR VSV the same thing as the EGR Vacuum Solenoid?

[Chris Crash]

That could be another name for it, not sure. VSV stands for vacuum sensing valve and it's electronic so it makes sense.