Vac Hose
wonder if it could be a non-vac flight of a sensor?
Where I can get a vacuum hose C2500 88-94 DIGRAM could cause a leak of a vac- rich condition, too, and could cause the O2 sensor failure code 33 and 45 blink code
Correcting the loss of vacuum in map sensor and can be corrected itself.If has the plastic vacuum lines check closely to check the wiring to assign codes cracks.Also sensor.Delete disconnecting the battery for a couple of minutes.