my car is still getting horrible gas mileage!!! this is what i had replaced at the mechanic on wednesday:
starter
2 front o2 sensors
spark plugs
fuel filter
coolant temp sensor
also i got a full tune-up
i also just had the knock sensor replaced last saturday

after all this work and about $1000 im still not even getting 200 miles to a tank of gas. and no i dont push the throttle all the way down, i was very VERY easy on the car the last couple of days since getting it back from the mechanic. car runs super smooth now but i just dont understand why the horrible mileage. and i always use 93 premium gas. there is no cel and no hidden codes, i got 0505 when i did the check. anyone got any ideas?

 

how many miles do you have? Has it been in any wrecks before?

 

Did your mechanic check the engine's timing with the tune up? That is usually included in a major tuneup. If the timing is off, then somewhere within your emissions, is not working properly or faulty. The reason why I say that is because the timing on the VQ isn't adjustable because the ignition system is distributorless. Instead each spark plug is controlled by its own ignition coilpack. The ECU controls the timing and the ECU's ability to control ignition timing is based on the feedback it gets from the vast sensors throughout the engine which is mostly emissions related. First, check your air filter. Put it up against a bright light, if you can't see light thru the filter element, then replace it. Second, check your tire pressure, make sure their PSI matches what's recommended. Believe it or not, tire pressure affects fuel consumption. Third, check the brakes, also did you recently adjust your e-brake? Drive your car around for 5 mins, then pull over and get out of your car. If you sense a burning smell from the wheel wells, it's probably your brake calipers getting stuck dragging the brake pads on the rotor as you're driving. That will definitely affect fuel consumption and the life of your brake pads and rotors. Then, try cleaning the throttle body and IACV valve with intake cleaner. These areas usually accumulate carbon build-up which is detremental to engine performance. The knock sensor should be the last thing in the list because its the most expensive item and the KS code is usually set off by another code related to another engine component. Good luck!

 

Reset ECU, after normal driveing for 3 days, the car should get better MPG. BTW What brand gas are you using? Try to add some BG 44k or Marvel's Magic Mystery Oil to your gas tank.

 

Get a Budget y-pipe so the pre-cats are gone. Clean out your engine sludge: http://www.auto-rx.com

There is an emission recall on some 96s so ask your dealer if your VIN is a part of it

 

Check your tire pressure. If it's low it'll destroy your gas mileage

 

how does tire pressure affect gas mileage? and its a 96 gle with 117k miles

 

fuel injectors? clogged ones will destroy your gas milage

 

When you inflate your tires your car will run along smoother. Think about it if your pressures were low, the car won't move as easily. Just pump the tires up to around 30 PSI or so. Get some Sea Foam as well, good stuff.

Throttle body could be dirty.

 

A better explination is that when you have low tire pressure the contact patch is wider, creating more rolling resistence and friction. With a harder, more inflated tire you decrease the contact patch and reduce friction allowing the car to move easier and increase your gas mileage. 30psi is too low, try 40.