Looking for user history regarding their solution for MPG drop

array7 · 2007-11-13T23:05:52+00:00

My MPG suddendy fell almost 90%, and then another 30% with the nextgas tank.The dealer pretty much hinted that they would rip me off, since my caris OBD-I (88' injector V6 Olds).What I'm looking for is personal history of people who dealt with aproblem like this and what was the final cause that got the car backfrom the dead.Basically, I'm looking for pointers to start self-diagnistics.In my case - air filter is clean, spark plugs/wires are relativelyfresh, thermostat & engine coolant sensor are relatively new, andreport ok on the dash.I do know that the cat is somewhat clogged, but in the past in thesimilar condition it didn't cause the MPG drop to such extent.Car rides very smooth, which probably means that there's no rust onbrakes/wheels.In the essence, I'm close to be making only 1/3 of normal mileage atthis point, highway or not.

Nov 13, 2007 21 Replies

Rate this thread:

array7 18 years ago

We have a winner - replaced spark plugs and slark plug wires (one of them was broken at the tip where it touches the ignition module) - and the mileage is back to 20 MPG.

Vote

Edwin Pawlowski 18 years ago

We have a winner - replaced spark plugs and slark plug wires (one of them was broken at the tip where it touches the ignition module) - and the mileage is back to 20 MPG.

Keep in mind, if the plugs did not fire properly raw gas can get into the cat and ruin it. Don't wait so long next time.

Vote

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required