Hello first time post. I have a 96 lexus es 300 and i have desperate question i have read that the code p0401 insufficient gas flow is attributed to egr circuit, egr valve, egr modulator and the vsv are usually the problem but i changed the first 2 which leaves the vsv i need to know how much one runs for approximately and if i can buy one online for a reasonable price??

 

Have you checked the EGR position sensor? It is common to fail. And if it fails, it will not indicate EGR flow, and cause a code. Have you applied vaccuum to the EGR sensor to see if it will open and flow?

 

no just the egr valve and the modulator that sit on top of it. can you tell the location of the position sensor?