Deck Plate & 3.4 V6 MPG Issues

[Bstrom]

I did the Airbox Deck Plate Mod today and earned a CE light for it. Have put the cover on the opening and will see if it goes away. Still, I'm not getting the MPGs I should - almost half what I get on my '03 Tundra 3.4 V6!

All maintenance is up to date: new plug wires, plugs changed 8k miles ago by PO, new fuel filter, oil change last week, clean air filter, etc. Can't see what would be the issue - unless I have a failing O2 sensor (no CE yet) that is not playing fair.

Any ideas?

 

[csp]

Your check engine light probably has nothing to do with the actual deckplate. Most likely a sensor wire didn't get plugged back in or there's a vacuum line off somewhere.

Not sure why you thought the deckplate would do anything for fuel mileage, if I'm reading why you did it correctly.

 

[gamefreakgc]

Deckplate just opens up the air intake a little bit, it's not really going to help MPG's much.

Most MPG issues are because of either failing O2 sensors or a dirty MAF sensor. Try taking out the MAF out of the intake and cleaning per the photo tutorial on these forums (search "cleaning MAF" or something like that) since it's free and takes 15 min of your time. If not, it might be time to replace the front O2 sensor ($40 on Amazon).

 

[AZBub]

it's more common for the rear o2 to go bad. if your o2 sensors are 14+ years old it may not be a bad idea to replace both.

What plugs did the PO out in there?