'90 Pontiac 6000LE - check engine diagnostics

Hi everyone :)

I just bought a 90 pontiac 6000LE 4cyl and I'm trying to get it running as it should. I need help!

Computer codes being generated are 14 and 45. 14 is the coolant temp
sensor (running hot) and 45 is the o2 sensor (running rich). The car
is also drinking gas and the exhaust leaves a black soot patch on the
ground.

When the check engine light is on, the speedometer needle doesn't
move nor does the odometer. From time to time, the car diagram on the
instrument panel will quickly flash and suddenly the speedometer
kicks in and the check engine light goes out. Cruise control only
works when the speedo works. Also, when the check engine light goes out, there's a noticable increase in the engine's power.

I did a visual check of the o2 sensor and it looks like it might be
new. If I'm correct, the coolant temp sensor is on the drivers' side
just below the thermostat? That appears to be new as well.

If anyone out there has any advise on how to go about fixing this problem, I'd be very grateful.

Thanks!
George

I went round and round with mine, testing/replacing EVERYTHING and nothing worked till I got to the computer. I bet its your computer.

you've either got a broken ground strap or a bad ecm. Try tapping on the ecm to see if you can get it to change, if it does while tapping on it, you found your problem. On the keep it simple side, check the battery cables and make sure they are not frayed, and that they are clean and corrosion free.