check engine light on 1997 ford expedition?

Question

what can be wrong? check engine light on. electrionic machine hooked up, oxegen senser bad, replaced engine sensor, and exhaust sesor, but light still on. electrionic machine still says oxegen senser still needs repaired.

Answer 1

Well there are 4- o2 sensors so you may have replaced the wrong one and it will not clear until you have the ecu/ecm reset which can be done by unhooking the positive battery terminal for about 15 minutes.

Answer 2

The following is assuming you are dealing with disc (front or rear) brakes. Well, the first step would be to bleed all the wheels starting with the right rear (RR) then LR, RF, LF. If you're bleeding them by yourself I'd used a small hose, that fits tight on the bleeder and is about 12 to 16 inches long, that goes into a clean bottle partially full of clean brake fluid. Don't open the bleeder more than 1/2 a turn. Make sure the end of the hose is all the way into the brake fluid, that way as you release the brake pedal on each stroke no air can get back into the system. I'd do 8 to 10 strokes each (never let the master cylinder run out of fluid). Although the master cylinder may have been damaged if it ran empty before your repair, it will usually have excessive travel before you feel any braking, not feel mushy. If your sure you have no air in the system (someone can look at the bottle as your bleeding to see if any air bubbles are still coming out of the hose) then you most likely have sticking calipers. This happens when the piston seal starts to grab onto the piston (could be for a number of different reasons) and it prevents the piston (and the pads) from moving freely to quickly grab the rotor and then stay close to the rotor (a bad seal will also pull the piston and pads away from the rotor, not giving you that solid "braking right now" feeling. You can test this by applying the brake pedal fully and then having someone clamp a brake hose with brake hose pliers/clamp. DON'T use anything else! Brake hose pliers (or clamp) has a special broad smooth surface that won't damage the hose. Release the brake pedal and apply it again. If the pedal feels hard now that's the caliper that has a problem. Redo that for each wheel. I'd suggest replacing the calipers in pairs (both front or both rear). Take a good look at the pads and rotors (I'm assuming you did this already but just incase...) If the rotors have heavy grooving, rusting or pitting within the wear area, replace the pads and rotors in pairs (as above). Also remove the pads and take a good look at the back of them; Make sure they don't have a bent or rusty shim and that the contact area between the pads and caliper piston looks clean and solid. This can be a problem for phenolic (non-metallic) caliper pistons. Ok, time for me to stop talking :)

Answer 3

Expedition Engine

Answer 4

our engine light came on in our 1997 ford expedition

Answer 5

The wires to the oxygen sensor are bad. If the code says high voltage, it's a broken wire or connection. If it's the one for low voltage, the wire is shorted somewhere. The connectors on those get shorted or corroded a lot.
And pay the $90 for the OEM sensors. Not the generic stuff.

Answer 6

The Check Engine Light will not go out on its own, it must be extinguished with the code reader, or in the case of Ford, disconnect the battery for 15 minutes.
CAUTION-----> If your radio is custom or has a security feature, disable it before powering the truck down.

Good Luck

Answer 7

This may sound silly, but MAKE SURE the gas cap is on snug! That can set the Check Engine Light off - I used to sell Fords, and they actually had us tell customers to check the gas cap first if the light came on! Good luck!

Answer 8

did you clear the error codes off your car computer before you started your car? the code will always come back until you clear it.

Answer 9

what is the code there is more than one code for O2 sensors

Answer 10

It may be the EGR valve.