engine light

I have a 1999 jimmy slt 4dr 4x4. My gas gauge only works when it wants to and my engine light keeps coming on for the bank 1 o2 sencer. I've changed it 3 times in the past two weeks if anyone can help me with any of these problems or has any advice i'ld love to here it.

First lets deal with the "Service Engine Soon light". What is the DTC (diagnostic trouble code) it is giving you? It will start with a "P" and have 4 digits after it. Did you check the circuit and the sensor and confirmed a faulty sensor? Or did you just replace the sensor? Which sensor did you replace? Did you clear the codes after each replacement? What are the driveability symptoms? Has it had driveability issues in the past? Give me a little more information to work with.

I'll have to get back with you on the code but I know it was for the bank 1 o2 sensor. The only drive ability issue i've had was when my fuel pump went out on me about a year ago. This may sound stupid but what circuit are you talking about.

When DTC's are given, the diagnostics include checking the circuits to the part first, then the function of the actual part itself. If there's a problem with the circuit to the part, replacing the part obviously will not fix the problem. Each DTC has it's own unique diagnostic troubleshooting sequence to locate and repair the problem. In your case, each oxygen sensor can trigger several different DTC's depending on what the malfunction is with the sensor itself. I would have to check the schematics, but I think there are 4 oxygen sensors on that vehicle. Which raises the question, did you replace the right one? Or is it a wiring problem? Post the code here and we'll see what we can do.

I took it to a gm dealer and they scanned it and said that it was the sensor itself. I told them I replaced it 3 times. So they erased the code and disconnected my batt. for a half hour. So far the light is staying off. Butt if there is something els you think I should do please let me know. If not do you have any ideas on my gas gauge.

Hopefully that will take care of the SES light. The oxygen sensor monitor is one of the first monitors to be completed after resetting the OBDII. After the engine is at operating temperature, it takes less than 5 miles of driving.

What are the particulars with the fuel gauge? Does it shows empty, full, or somewhere in between? Does it fluctuate back and forth? The most common cause for an erratic fuel gauge is the fuel level sensor in the tank. They are available separately however, the fuel tank needs to be dropped and the pump/module assembly removed to replace it. If it is stuck on full, look for an open circuit. If it is stuck on empty, look for a short circuit.

The gas gauge use to read full for a cuple days and then go to empty for a cuple days. Now it will somtimes get stuck on full but then it will go to 1/2 or a 3/4 tank it's never rite. I've had some people tell me i need a fule sending unit but every where i look they tell me i have to buy the whole pump ass. and some people have sead that it's just a bad groung. The whole pump ass. was replaced about 1 year ago. if it is the fuel level sensor where can i find one.

If you don't have a crystal ball in perfect working order, make sure you check the circuits and connections before you just replace the sender. It may not be the problem. It can get rather expensive in a hurry guessing what part needs to be replaced.

If it turns out that the fuel level sender needs to be replaced, this site http://www.gmpartsdirect.com/ and the dealer will have it available without buying the entire pump and module assembly.