Q: Obd codes 33,34, and 43 what does this mean? 1993 Chevrolet K1500

asked by on February 25, 2017

Runs rough, misfires, hard starting, stalls when stopped

My car has 200000 miles.
My car has an automatic transmission.

Hi - the diagnostic trouble codes you mention are: 33- Manifold Absolute Pressure circuit/sensor malfunction: wiring open circuit/shorted circuit to positive, hose blocked/leaking, MAP sensor, 34- manifold Absolute Pressure circuit/sensor malfunction: wiring shorted to ground, 42- ignition control module circuit problem (running on default timing curve). These collectively sound like engine wiring harness issues, or perhaps a bad engine to chassis ground, or engine/chassis to battery ground issue. I recommend a running rough inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.

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