leflore

I have a 2007 Honda Civic EX which is getting pour gas mileage. Do not have any CELs however looking at live data on ODB scanner, I am seeing 99.2 % EGR Error Rate. What does this mean? Could this be a bad EGR unit?

No, I have not changed the plugs yet.

Thanks for any info.

vtecnique69

clean or replace egr valve. Should clear things up.

how many miles on your car, and any mods?

leflore

Its actually my 20yr old daughter's car. That may be part of the mileage problem.lol It has 61000 miles on it so i am going to change the plugs also. Thought I was going to do the fuel filter until I saw it was in the tank. I will try cleaning the egr first. I am just curious why it is not throwing a code. Thanks for the info

vtecnique69

well its probably still working, just not as efficient.

Plugs might help if she beats on it, as would new oxygen sensors.

If she has a lead foot, as you may have implied, that definitely won't help things.

what gas mileage is she getting currently?

leflore

She says she is getting 14-15mpg. I bought plugs yesterday. Ngk plugs cost me $60.00. Afterwards I looked on line and could have got them fro amazon for $45.00. Oh well, live and learn

leflore

Cleaned the egr but still getting the 99.2% error reading. Guess I will buy a new one. A little apprehensive however. On my other vehicles it's never been the egr itself. Of course the other ones have been mechanical with vaccumn lines etc.

leflore

New plugs and EGR valve. Air filter is clean. Tire air pressure is normal. However, my daughter says she is still getting bad gas mileage. What should I check next? Thanks

vladd

I would look into the air filter and oxygen sensor. The air filter should be changed every so often (no idea what the recommended mileage is), the oxygen sensor should be OK with only 61k miles, but if she's only getting 15 MPG on a non-Si, something is obviously wrong.

leflore

Thanks. I will have my friend check it again with his scanner and will see what the live data is reading on the 02