Originally Posted by Slacker87

I have a 93 Mazda Rx7 that is getting around 200miles per tank. I have only owned the car since December so I do not know the history of it. It does however have a 3 inch exhaust pipe from header back (I THINK) it does have a glasspack or high flow cat. I am not sure if it has the precat or not. I am also not sure if it has the stock downpipe. The other day I noticed the downpipe glowing orange at night after warming up for about 5 minutes. It does have the AWS connecting and working. I do not smell a strong gas odor coming from the tailpipe it just smells like a little bit of burning oil. Most of my driving is done on the interstate at about 80 and some surface streets around 60. I drive the car 40 miles a day. It was 20 something degrees outside at the time. So to my real question what should I look at replacing first? O2 sensor, injectors, engine temperature sensors all three of them, fuel filter? Please point me to the a tutorial on how to do those if you know of one. I am slow at using the FSM.

Originally Posted by dgeesaman

I suggest you change the fuel filter as a matter of maintenance, and at your next convenient time, get the injectors pulled for ultrasonic cleaning. Glowing dp during warmup suggests you have an injector dumping fuel.

Dave

Originally Posted by scotty305

You still don't know your Miles Per Gallon, although it's not too tough to find:

1. Start with a completely full tank
2. Zero out your tripmeter
3. Drive until nearly empty
4. Fill the tank completely full (try to use the exact same gas station both times)
5. Write down how many miles are displayed on your tripmeter.
6. Divide the miles you travelled by the gallons of fuel you used. For instance, on my previous tank, 192 MILES / 13.98 GALLONS = 13.7 MPG

-s-

Originally Posted by R-R-Rx7

i cant be asked to read all those replies but i would check for exhaust leak aswell