Trouble code 34 and 45

[Jorge6.5]

I checked for codes on my '90 Chevy k1500 with 305 since the check engine light is illuminated. The codes that came up were 34 and 45.

What do these codes mean and what could be the cause and fix for them?

The truck will sometimes have a lack of power and will buck or hesitate. The truck actually stalled twice today while going down the road. The idle can be a bit off and rough at times.

I have recently done a tune up but the truck is the same before and after. I used mostly ac delco parts, cap, rotor, plugs and wires. A new air filter and msd ignition coil. I have yet to replace the fuel filter.

Thanks guys.

 

[burkey05]

I checked for codes on my '90 Chevy k1500 with 305 since the check engine light is illuminated. The codes that came up were 34 and 45.

34. Low voltage (high vacuum) at MAP sensor

45. Oxygen sensor rich

google is your friend

 

[Jorge6.5]

I found that much in my chilton repair manual. I was looking for help on what would cause that and how to go about fixing it

 

[burkey05]

I found that much in my chilton repair manual. I was looking for help on what would cause that and how to go about fixing it

have a look at post 18 of this thread, it tells you how to test the coolant temp sensor(possible cause of code 45) and MAP sensor testing(code 34)

http://67-72chevytrucks.com/vboard/showthread.php?t=357014


i find using google or searching on forums is the best and quickest way to get your answers.

yours is not the first truck to set these codes, the answers are out there

 

[Jorge6.5]

Well I picked up a new coolant temp sensor, replaced that and now I'm only getting code 34. While driving the ses light will go out and come back on several times. Still have lots of bucking, hesitation and lots of fuel consumption. The truck sometimes feels like its ready to die and has stalled today at a red light. Come Friday I'm gonna replace the fuel filter that I've had for it, recheck all vacuum lines and connections. Might just go ahead and replace the map sensor. Also read someone was having a code 34 and turned out to be the ECM. The carb swap is looking like a much better idea at this point