my p5 has a bad fuel consumption. what are the possible cause?

[The_big_dill]

This guide and the whole thread are awesome but doing this recently, I cannot stress enough how bad the screws are. The bolts are taken out easily enough with a tiny ratchet and shallow socket but the screws... They wanted to strip without any pressure at all. We had to take a torch to them and pull them out with pliers.

Yes, if you are rebuilding the EGR, then the screws that hold the little motor are made of nothing sturdier than swiss cheese.

However, you shouldn't need to rebuild the egr as lubricating the spring doesn't solve the issue. The problem is internal rusting of the motor which you cannot replace. Rather you replace the egr as a whole as its a common maintenance item anyway.

 

[pcb]

Go with the Canadian version...

It's a bit of work to install but you'll never have to deal with it again.

 

[rit14623]

Do you have lower power?
Did you ever run the car for an extended period of time with a CEL issue related to a bad coil or dirty EGR?
Is your upstream catalytic converter clogged by any chance? When mine was clogged, it blew out the gasket between the exhaust manifold and cat's flange. Fuel economy was in the low 20's MPG with conservative highway driving.
When I replaced the catalytic converter, exhaust gaskets, upstream O2 sensor, EGR valve, coils, wires and plugs, the power went back to normal, noise from the blown gasket went away, and fuel efficiency came back to the low 30s MPG with conservative highway driving.