I had a quick question...
My 2000 Cavalier runs and drives great!! Other than a slight vibration at idle?
But it is idling at the correct rpm.... just the car shakes almost haha
But for some odd reason, I'm getting about 200 miles to a tank.
I put $40 in and it only lasts maybe a week....
I was curious as to if ya'll could help me out in finding what might be killing my gas milage.
The car has B&M shift plus. And I know the valve cover has some writing on it. Could it have larger injectors? idk.
Help me out in fixing this? Haha
possible fuel leak? when was the last time it had a tune up ( plugs, wires or boots depending on your engine air filter fuel filter) also i would have you 02 sensors checked at that would cause a drop in mileage as well.
There is no smell of gas. So I don't think there's a leak of any kind.
I know there's a small exhaust leak. My 4-1 Header is cracked a little. You can hear it.
I'll replace the plugs wires and boots this weekend?
And I'm going to replace the intake filter also I know it looks colgged a bit.
I just didn't think that could be killing my mileage so bad....
Any other suggestions?
Or is that pretty much what all it could be?
tune up, o2 sensors, plugged cat? Any codes or dash lights on? anything? Change anything recently?
I know the airbag light is on.
But thats from the previous owner installing a racing stereing wheel.
Havnet done much really.
I know the idiot had the cold air intake right infront of the hoodscoop hole in my hood.
So the filter is filthy. And probably was wotter logged a few times. :/
I'm going to look into the Plugged Cat!!! But I don't think it is. The car has almost new cat back exhaust.
"I know there's a small exhaust leak. My 4-1 Header is cracked a little. You can hear it."
If the crack is pre O2 sensor it can cause a faulty reading and a rich condition.
mitdr774 wrote:"I know there's a small exhaust leak. My 4-1 Header is cracked a little. You can hear it."
If the crack is pre O2 sensor it can cause a faulty reading and a rich condition.
agree'd i think he should have noted that in the original post. i think that is your problem. get it welded and i will bet that solves the issue
the_miker17(u kiddin) wrote:mitdr774 wrote:"I know there's a small exhaust leak. My 4-1 Header is cracked a little. You can hear it."
If the crack is pre O2 sensor it can cause a faulty reading and a rich condition.
agree'd i think he should have noted that in the original post. i think that is your problem. get it welded and i will bet that solves the issue
I second this statement. I have a wideband, which had accidentally had one of the 5 wires cut. The result was that the sideband read too lean, only by 2.0 AFR points, so instead of 15.7, it read 17.7. Anyways, because the computer thought it was always lean, it was dumping the max fuel in the car. I had the same milage problem. about 190-200 miles to a tank. I fixed the O2 sensor, and everything is working again.
If your crack in the header is allowing extra oxygen into the exhaust, then your sensor will think the car needs more fuel because it see's too much oxygen.
Alright.
I have a spare 4-1 stainless steel header sitting brand new in the basement.
I'll go ahead and throw it in the car and see if that helps.
I'll throw it in, hopefully this week or next haha.
Think a clogged intake would hurt too though?
I have a new cold air intake....
But there is no inner fender, and no cover for it. So won't it get water logged down in my fender? cause the body kit bumper lets air though easy.
Carbon canister selonide or purge selonide
see ya!
I had a similar issue happening recently in regards to the rough idle, I had to replace the throttle body and the Idle Air Control sensor along with the throttle body itself.
A worn down front motor mount can cause extra vibration as well, just went through that one too.
I installed the new header
Modified an aftermarket intake, so that it was under the hood instead of in the fender(so that it has a new filter away from hood scoop away from water)
Ran some fuel injector cleaner
New wires installed
New plugs....
The car seems to be running pretty good now.
Thank you all for the help... I'm getting about 320 miles to a tank now.
