gas mileage problems

[Silver 99 Camaro]

Recommended O2 sensor change interval is 100K for just about everything.

[dorkins]

then what else could be m prob.?

is there a way to test the o2's before i go out and spend that much money...?

[navyblue2000]

the cold weather doesn't help. not one bit.

aftermarket thermostat? if you do put the stocker back in.

what trans do you have?

[V6viper]

you could try seafoam, i just used it and it upped my gas mileage a good 40 per tank (no bs)

[IKu]

could be the way you're measuring... try filling the tank all the way and taking note of the miles on the odometer, then drive to near empty, fill the tank all the way and take note of how much gas it takes to fill and what the odometer now reads. then do the math. maybe you're already doing it this way, but the way you vaguely describe your measurements leads me to believe you're just driving to the e line and calling that a full tank used.

[dorkins]

are there any detailed instructions on how to use sea foam? where to put it all... pictures?

[Silver 99 Camaro]

Typically when O2's are bad they will trip the SES light. Otherwise they are usually fine up til 100K.

I live in Cleveland, and I see you (dorkins) are from NE Ohio. My gas mileage goes down in the winter. The engine uses more gas, then of course spinning the tires in snow, and most of all, here they swtich to oxygenated gas during winter months. I will avarage 20-22 MPG in summer and only 18-20 in winter. Yours is still lower than that, so you might have a problem.

My advice...FORGET ABOUT THE O2 SENSORS AND SEA FOAM; CHANGE YOUR PLUGS AND WIRES! We have all had those go bad and before you go removing parts that aren't broke do the simple thing, TUNE IT UP. Tune up does not mean PCV valve and fuel filter only.

Good luck!

[dorkins]

when would be the best time to use sea foam?

what do i need to know when changing plugs and wires?

any walkthroughs for it, or for the sea foam?

do i need to gap the new plugs?
what kind should i get?
and, what should i look for in wires?

i live in warren btw

[Silver 99 Camaro]

SEARCH. Tons of posts on both topics.

[V8 Killer]

could also be a clogged cat or incorrect timing.Try using a different gas station (bad gas?)

[terminaldegree]

If you get the AC [NGK] iridiums, I think you're supposed to gap them to .060"

The iridium electrode is VERY fragile. In my experience, with a feeler gauge, they are close to correct right out of the box, which is good cause I don't want to break one at $6 each.

Stock AC wires will fit well of course. Route them carefully so that they don't touch anything that gets hot. Reuse the metal heat shields over top of the wire boots near the engine.

To remove the wires, turn the metal boots to break them loose. Turn the wire boots back and forth to break them loose. Pull only on the metal boots and the wire boots, not on the wire themselves. It will take some effort and wiggling. REPLACE WIRES ONE AT A TIME TO AVOID CONFUSION.

Use a plug wrench instead of a regular socket for the spark plugs with a short extension for the ratchet. For fear of cross-threading, I use the socket alone [w/o ratchet] to insert the plugs at first, and then tighten with the ratchet.

Of course, all this is easier with a cold engine, and with the 2000- later stock tubular manifolds.

p.s. if you're going to mess with Seafoam, just err on the side of extreme caution-- don't feed it too much/quickly. It's rare, but seriously bad things could happen.