Hello all,

Was wondering if anybody could shed some light on my issue. I had a CEL pop up (P0405) EGR low circuit. I replaced the EGR valve, cleared the CEL with my tuner, and the light hasn't come on since. Great. However, since I replaced the valve, I have lost 2 MPG's!! Is clearing the code with my tuner good enough, or should I disconnect my battery to reset the PCM so it can learn with the new egr valve?

Any help is greatly appreciated.

 

might be time for plugs and throttle body cleaning?

 

I guess it couldn't hurt...but the decrease started right after the egr valve change. I guees it could just be a coincidence.

 

Are you doing hand calc's or overhead? Overhead compiles an average over a loooooong period of time. Hand calc is most accurate.

When is the last time you actually calc'd it? Do you do it every tank?

Last but not least....The TCU needs to "learn" your driving habits so that could contribute to lower fuel economy until it's found out the sweet spot for you.

 

Ya that stupid Overhead...I hate that thing sometimes. I will hand calculate for the next couple of tanks. i did notice, however, that the last tank I got approx 50km less out of a tank full. Should I reset the PCM to account for the new egr valve?

 

I read this too quickly and thought '50,000 mi on a tank of gas?', then realized you were referring to kilometers lol

 

I thought it was recommended to unhook the battery cable before changing the EGR anyway.

 

ya you're probably right...i never do, but i guess i should be!!

 

Ya up here in Canada, we go metric!

 

Blacksport,

You really should unhook the battery and reset the Computer