when i put on my vacume gauge on my car and started it it said 14 of vacume but when i hit the gas it went to 2psi positive pressure am i reading my gauge wrong or is this normal? i unhoked the line and put my finger over the end and shure enough when i hit the gas it starts to push out slightly rather than pulling more. I thought vacume was supposed to build with RPM.

 

that's a low vacuum number to start with, and unless you've got a turbo/super charger, you shouldn't be getting positive manifold pressure.

which port are you tapping btw?

 

the one for the EGR cause the light keeps comin on and thats the only code i get. well mabe my gauge is off and its just goin to zero but at any rate that is still weird.

 

youre gonna get pressure at the egr to open the valve. tap into the vacuum port on the back of the manifold and you will get a good vacuum reading. and if youre getting a code for egr, your solenoid or valve may have problems. check and see if the valve is moving by pushing up on the diaphragm. it may be sticking.

 

Our cars don't set a code for a non-functional EGR valve. They set a code for not getting a vacuum signal to the EGR Sensor for whatever reason.

Check to make sure that you are getting vacuum to the EGR solenoid, then check the line going to the EGR Sensor that's mounted to the egr solenoid bracket. You should have no vacuum then a signal when you snap the throttle open.

All our cars check for is a vacuum signal...they assume that the EGR valve itself is actually functional.

If you get a positive pressure reading when you sanp the throttle and are hooked up to a manifold source, then you have an exhaust restriction(most likely a clogged cat) that needs to be adressed

 

have no cat and the y pipe back is only 6 months old.