Okay...

I am looking for ideas here....

About a month ago, I rode from Dallas to Houston, and I made what I thought was good mileage, about 26 MPG

Now this weekend, I've have noticed a significant drop off...and I am trying to find a solution here's what I know:

1. I have an exhaust leak, probably in the front manifold. I am replacing the gaskets and studs this weekend.

2. My O2 Sensor has a small dent in it, I may replace it, but as expensive as it is, I like to know if it can be checked before I just toss it and get a new one.

3. I replaced my spark plugs about this time last year, and I may consider doing that again when I inspect them this weekend (I use OEM NGK's from the dealer).

4. I am planning to run SeaFoam through my intake (I do this every 6 months or so).

5. I am going to clean and/or replace my K&N filter.

6. My VTC harness (which I keep grounded) recently showed signs of an oil leak. I had to replace the harness, individual wires that I soldered together to again kill the clacking. BEfore I did this, I noticed a power loss , as well as the gas milage loss, but the power has seemed to return.



Any other things I should replace/clean/inspect?

Knock sensor and MAFS were replaced about 2 years ago

 

- ECU tests contain one tst specific only for O2, read also FSM
see http://www.cardomain.com/ride/748507/21
- EGRC temp sensor
- Hand brake; wire stuck
- gas leak
- intermittent injector leak

 

You may want to visually inspect your vacuum hoses to see if any have cracked ends. Those cracks develop 'all of a sudden' and cause all kinds of nasty effects. Is your braking feels worse by any chance? That would point at vacuum as well.

 

This problem is most likely the majority of your bad gas mileage problem...

 

When I had a leak from the flex section and 4 broken studs on the back, by bad gas mileage was not much worse, than now when the problems were fixed.

 

my car got **** mileage because of a bad flexpipe

 

I've been siphoning your gas. Sorry.