Code 45

Nov 02, 2005 5 Replies
S

'87 Chevy G20 Van...1000RPM when cold, 15-1700RPM when warmed up, starts great, good vacuum, great power...



Got a code 45 which is a rich condition(at the O2 sensor). What specific areas does everyone think(or know) I should look at before changing the O2 sensor(if needed).



...Injectors, MAP sensor, IAC solenoid, TPS, FPR, fuel filter, Fuel pump, cap and rotor...all good. New EGR valve, EGR solenoid, and timing set. Plugs look great and wires all have good Ohms. I should probably change the plugs and wires before the snow falls though huh?


What's everyone's ideas, opinions, and experiences about this?


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C

The high idle when warm should be your clue. Fuel Injected vehicles idle Higher when they have a vaccume leak, where as carburated vehicles idle lower.

Warm in gear I beleave the idle for that van (check the emmissions decal for better info) should be about 750 to 850 RPM's. The van probably has a thermial vaccume switch on the thermostat housing. Test by plugging vaccume lines together and let vehicle get up to operating temp. if Idle drops to a more normial range, the thermial switch is bad. If no change, try running a new vaccume hose from the destination of the switched vaccume. Charles

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S

Good point...I will check it! Thanx!

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S

ALSO a good point...I will check that too!

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R

Coolant temperature sensor, if it has one. I think it's another one of the gadgets that helps the computer to set the idle mixture. If it tells the computer it's zero degrees when it's not, then the mixture is going to be richer than needed.

I hope I got that right, I'm sure somebody will help me out on it if I didn't.

RJ in WV

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