Help my bonnni

I have a 92 bonnni supercharged. It eats up alot of gas. A half a tank wont last a day (avg. 15/20 miles). It's hard to sart. It cranks good just hard to start up. New starter, fuel pump. spark plugs and wires, and coil. Trouble codes reads 26 ( Quad Driver ) 55 (EGR Fault) 57 (Boost control Problem ) and 58 (Security system <fuel enable circuit> ) what could be causing this. My gauges on my dash also go haywire. Any suggestions. The car has 135,000 miles. :banghead:

First of all change the Oxygen sensors as they are probably causing the car to use fuel. Second remove and clean the Egr valve. Simply remove it and spray the underside to clean the passageways and the operating portions of the valve. As for the boost control problem you probably have a bad boost control valve on the supercharger. It will probably need replaced due to age. Not hard to do but can be expensive. As for the guages check the body control module. It sounds like the module is going bad and it is not allowing the guages to work right. I am sorry I don't know where it is located on your car. Also you may want to clear all codes in the computer after you do some of the work to see if they come back on. They may be stored codes and are not truly indicitive of what is going on with your car.

Thanx will try. I will keep u posted. Glad to see people help out on here!