My service engine light came on due to codes P0400 and P0136. After troubleshooting i found a broke hose on the EGR which i replaced. I cleared the codes expecting the light to return with a P0136. I've driven 120mi over a couple trips/days and still no light. Was the O2 sensor problem caused by the EGR problem? Has fixing one problem solved the other?

Ernest Stalker

• 53 Answers
• Posted on Jan 15, 2009

SOURCE: no vacuum to egr valve

there is an EGR vacuum solenoid somwhere that controls on/off vacuum to actuate the valve. i am not to sure of the location, but follow the vacuum line back from the egr until you find a device that looks like an electrical check valve for vacuum. that is a possibilty. but then again i am a ford,chrysler guy and am just giving you an answer based on my understanding of the functuality of a vacuum egr system

SOURCE: code p0400 keeps coming up after changing the egr valve and sol.

You need to check the passages from the egr valve to the intake to see if there is excessive carbon buildup thereby blocking the passage to the intake. The principle is that when the test for the code runs it is to determine if the egr system is operating correctly. It opens the egr valve to lean out the fuel mixture an so determine if the system is operating correctly. If the code is for electrical operation of the valve it will be an electrical issue